EastEnders star Natalie Cassidy has lifted the lid on her character Sonia Fowler’s strife amid her fight for freedom.

Sonia is currently on trial after being wrongly accused of murdering fiancé Reiss Colwell’s (Jonny Freeman) wife Debbie last year.

As fans of the BBC soap know, Reiss actually smothered a comatose Debbie to death in her care home bed in a bid to solve his money woes.

He is also holding Sonia’s sister Bianca Jackson (Patsy Palmer) hostage in a lock-up after she uncovered his killer secret back in November.

With Bianca obviously unable to attend her trial, Natalie reveals Sonia’s pain as she believes her sister has abandoned her.

‘Sonia is so upset that Bianca hasn’t turned up to court,’ she explains. ‘She keeps saying, “Where’s my sister? Where’s my sister?” She’s really hurt.

‘Sonia’s daughter isn’t there and her mum isn’t there, so she was counting on her sister to be there for her and she isn’t. Sonia really needed that family support, and although Martin, Jack and Kat are there, it’s not the same as having her sister there.

‘Sonia really wanted Bianca to be around.’

Unbeknown to Sonia, however, Bianca has been plotting her escape from Reiss’ capture, determined to prove her sister’s innocence – but scenes next week will see her face many hurdles in her attempts…

Natalie also teased how pregnant Sonia is coping with the possiblity of giving birth to her and Reiss’ child in prison, branding it her ‘worst nightmare’.

She says: ‘I don’t think she could cope with giving birth in prison and looking after her baby in prison or having the baby and then the child being taken away from her. It would be her worst nightmare.’

Natalie – who has been on an extended break from filming EastEnders – also reveals viewers will notice a huge difference in Sonia’s character after her on-screen return, explaining that her ‘prison experience has a profound impact on Sonia’s character’.

‘She’s had a really bad time of it in prison. She’s been worrying that she might have the baby there, and she knows that she’s innocent, so her mind is whirring over who could have done this.

‘You see her change,’ she continues. ‘If you had been through an experience like that you would either harden or it would break you. Right now, Sonia is on the verge of make or break…’