Having been through various dramas during her three-year stint on the show, Imogen departs screens on a happy note as she leaves Letherbridge to go to art college.
In real life, Charlie is saying goodbye to Doctors of her own accord and is already in rehearsals for her next project, portraying Ela in Charley's Aunt at the Menier Chocolate Factory in London.
Digital Spy recently caught up with Charlie to hear the story behind her exit and her future plans.
Why did you decide to leave Doctors?
"I'd always mentally put a three-year timeframe on my time at Doctors, so I went to the producers in December and they were really lovely about my decision to leave. They asked me to stay filming until June, as that would allow Imogen to go off to art school in September. That was really nice, because I felt like I was a part of what was going to happen to Imogen, and I was kept in the know from the start.
"Once I made the decision to leave, I started auditioning - and my first audition was actually for Charley's Aunt, which I'm working on now.
"I think I felt like I needed to challenge myself differently again. I trained classically at the Guildhall School of Music and Drama, but I haven't done theatre for a very long time. I wanted to get back on the stage, and I had my heart set on doing something old - so I was really lucky that my first audition was for a period farce."
Were you pleased that Imogen was given a happy ending, or would you have preferred her to go out with a bang?
"I'm really happy with the way Imogen is leaving. I think it's the best thing for 'Team Hollins', because it's been the most incredible journey for the family. Doctors has never really had a full family with teenagers in it before, and I feel like the viewers really welcomed us into their homes. To have destroyed that would have been tragic, especially as they've already been through so much anyway over the past three years!
"Although a dramatic exit storyline can be interesting for the viewers, I think Doctors has already offered that with the fire, Freya dying and the separation of Daniel and Zara. There's enough turmoil going on! It's hard enough for Karen to deal with her children leaving, without it getting any worse than that!"
How do you think Doctors will cope with so many characters leaving at once?
"I think they'll recover brilliantly as usual. It's just unfortunate timing, really, because a lot of people's mental time limits just happened to tie in together. There's no other reason than that. Doctors have always supported the actor, and they've been very accommodating to everybody. I know that they've stayed true to every character in terms of their departure storylines.
"Also, the casting department at Doctors is brilliant - every single regular they bring in is so great to work with. You've seen already that they've brought in Ian Kelsey as Howard and he's brilliant, so there'll be more of that kind of thing to come. There's more new, exciting characters on the way."
Would you reprise the role of Imogen for guest appearances?
"I think that's a possibility - never say never. Obviously my main intention is to move on and experience different things, but I certainly miss everyone at Doctors very much. They've already said to me, 'Would you come back for certain events and the student holidays?'
"So there's always a door open, which is lovely. If it came up, it'd definitely be very hard to turn down!"
Were there any tears shed on your final day on set, or did you keep your composure?
"I didn't keep my composure at all! It was such a difficult last few weeks - it wasn't just the last day. I'd thrown my whole heart into the show, and Imogen had been so exciting and interesting to play. Once it started to sink in that it was coming to an end, I felt very emotional. I did cry quite a bit actually!
"I was monitoring things like the last time I had a scene with just me and Jan [Pearson], or just me and Nic [Woodman]. I really tried to soak it up, make the most of it and enjoy it."
What will you miss the most and least about working on Doctors?
"I'll really miss the car journeys I had with my fellow Hollins cast members in the mornings. We might have 18 scenes ahead of us and all sorts of things going on in different stories, so we'd know that it was the start of a really tough day. We'd all sit there and get ready for the day together, and I feel so grateful that I had those times.
"It's the teamwork - the whole crew and the whole cast. When you're together, you feel like a real unit. We wouldn't have got through it if we didn't have that, and it started to feel like the Hollins were a real family. We didn't have to try any more, it was effortless and there genuinely was a real bond between us.
"What I'll miss the least is probably bleaching my hair! The other thing it's important to remember is that a lot of people have to make sacrifices at Doctors. Because it's such a fast-running and low-budget show, every single person has to make a sacrifice in terms of their work every single day. There isn't necessarily time to rehearse, or nail it and get it brilliant. That's a hard condition to work under when you believe in telling the truth about something."
Does any particular storyline stand out as your favourite?
"When we filmed the abortion storyline, I learned an awful lot from Jan Pearson. She is an absolute pro, and she literally dragged us all kicking and screaming through that story. I've never seen someone just so good at what they do, so I enjoyed every moment of that, even though it was completely heartbreaking.
"For Imogen, that culminated in one of my favourite episodes to film - 'Pavlova's Dogs', where she was sick on herself and singing on the toilet! I always remember that was the day the family got back together, and it was one of my favourite scripts. It really marked a very proud moment at the end of a difficult story. So that I think is probably the most memorable."
Are there any others?
"Imogen's shoplifting storyline ended with 'Daddy's Girl' which was another big episode for me. I filmed that storyline all in one go - the stealing, the homelessness and the falling out with Rob.
"It was a really intense and exhausting couple of months, and I got a two-week holiday at the end of it. I went away and it literally took me days to switch off - it was all going through my head constantly!
"'Daddy's Girl' aired while I was away, and I had loads of lovely messages afterwards. I think if you can touch people who have been through something similar, which it seems that we did, then you have to feel very honoured and proud of the scriptwriters and the team behind you."
What can you tell us about Charley's Aunt?
"It's a comedy, it's a farce and it's very entertaining. I don't want to give too much of the story away, because I hope that people will come to see it without knowing too much of what is coming next.
"But I am a very small cog in a very talented machine. I'm playing a 17-year-old orphan girl, who gets taken under the wing of Jane Asher's character Donna Lucia and brought back to England. She's in love with a man who is played by Mathew Horne. He's dressed in drag in the play, so I arrive to find this old woman and unbeknownst to me, it's the man that I love beneath the wig!
"In terms of everyone else, there's a lot of running around and ridiculousness. It's really fun and very entertaining."
How are the rehearsals going ahead of opening night on Thursday (September 20)?
"The rehearsals have been fantastic. It couldn't be more different from what I was doing before - I've got a whole script to work with and we can tweak different moments every day, trying to make it better and seeing how far we can push ourselves. Losing the Brummie accent has been quite interesting! I don't have a Birmingham accent like Imogen does, but having done it for three years, I do slip into it quite often!
"Like I say, I'm a small cog in an experienced cast. I've been able to sit in a room and learn from people who have done this so often and so well. I couldn't have been luckier to literally go out and audition for one job, get the part and have it be exactly what I was looking for."
Will your Doctors friends be coming to see the play?
"I hope so! I spoke to Matt Chambers the other day and he'll be coming soon. Nic Woodman, Jan Pearson, Chris Walker and Danielle Henry will too. Some of them will even come and see it more than once, if I'm lucky! After previews, the show will start to change, as it's such a busy play and hopefully it'll keep getting better as we find our feet.
"But I've told the Doctors cast not to all come together! I don't want a whole row full of Doctors people, because it's quite an intimate space and you can see the audience sometimes. I'm notorious for getting the giggles on set, so I really don't want to get back into the habit of that!"
Would you appear in another soap in the future?
"That's a tricky one, because I feel like the reason that I left Doctors was not to repeat old ground. In terms of what I've learned and the skills, Doctors has offered me the best grounding. If I were to do something ongoing like another soap, then it would have to be a part that was very different and offer me a very different challenge.
"But the difficulty is that those programmes are producing some fantastic work at the moment. I guess it just depends on what it was, who it was and how long for! Ideally I'll be trying to diversify my work and choose some very different roles that maybe don't last as long."
> Read the latest 'Doctors' spoilers and news
Doctors airs weekdays at 1.45pm on BBC One. Charley's Aunt runs at the Menier Chocolate Factory in London between September 20 and November 10.