The actress, who plays Kat Moon in the BBC One soap, is said to have been given a break as she continues to get over her split from Vince Morse.
Show bosses have organised emergency script changes which have seen Kat called away to care for dad Charlie after he suffered a stroke.
"She's had a stressful six months," a friend told The Sun. "She's been given three months off and no one can blame her for taking a break.
"Jessie's worked solidly since her wedding nightmare and had already come back early from what would have been her honeymoon. It was a very easy decision to make for the show. She is a great actress and extremely popular on set.
"She'll come back stronger than ever. Jessie's convalescing after a long run and very stressful six months. She'll be back as soon as she's ready."
Wallace's spokesperson refused to comment on the report.
She called off her wedding to Morse in August last year after he sent intimate pictures of her to another woman.
> Jessie Wallace's ex-fiancé Vince Morse apologises: 'I'm sorry I've humiliated you'
> Jessie Wallace 'hides on EastEnders set to avoid ex-fiancé Vince Morse'
Watch an EastEnders character trail for Kat Moon below: