As announced earlier this year, the actress has been cast as Mercedes McQueen's cousin Jenifique for the latest run of after-dark specials on E4.
Viewers will see Jenifique for the first time tonight as she catches up with her family during Mercedes's hen celebrations in Ibiza.
"I'm so thrilled to be joining the show and I couldn't have asked for a better part," Walsh told OK Extra. "The McQueens are such a huge part of Hollyoaks.
"Jenifique's a great character. She looks up to Mercedes, but [Mercedes] doesn't like her and calls her the 'annoying stalker' cousin. But actually the two are very similar. Jenifique's very feisty, but she's a dreamer and a bit naïve."
Asked what Jenifique gets up to in Hollyoaks Later, she replied: "Well, she's going to be causing quite a bit of trouble! She's very brazen and likes stealing things. The show focuses on Mercedes's hen do and when Jenifique arrives, all hell breaks loose.
"It turns out that Jenifique is dating one of Mercedes's exes, so that doesn't go down well."
Amy is the younger sister of Girls Aloud star Kimberley Walsh and the part of Jenifique is her first major acting role.
Hollyoaks Later airs all this week at 10pm on E4.
> Hollyoaks Later Jorgie Porter interview: Will Silas kill Theresa?
> Hollyoaks Later Miles Higson interview: Horror ahead for Seth Costello
> Hollyoaks Later Jennifer Metcalfe interview: Ibiza surprises for Mercedes
> Hollyoaks Later Rachel Shenton interview: Mitzeee danger, romance and mischief
> Read more about the new series of Hollyoaks Later
Watch the official promo video for this year's Hollyoaks Later below: