Kate Winslet was ''nervous'' when she agreed to star in 'Wonder Wheel'.

The 42-year-old actress stars as Ginny in the recently released Woody Allen movie, and has said that whilst she was ''incredibly excited'' to work with the filmmaker, she found her character - who is an emotionally volatile former actress now working as a waitress, and is married to a man she hates - difficult to play, and was worried her performance would go ''wrong''.

She said: ''I just didn't think I knew how to play the part, I just didn't think I had the stuff to be able to do it. Everything Ginny feels is gigantic ... She's an awful mother, and I don't like playing people who are bad mothers ... There were many, many reasons why I was nervous to play it, because I felt like I could have got it wrong so easily.''

Kate admitted she was considering voicing her concerns to Allen and giving up the role she was offered, but her 17-year-old daughter Mia - whom she has with former husband Jim Threapleton - convinced her to go for it.

The blonde beauty - who also has 14-year-old son Joe with ex-husband Sam Mendes, and four-year-old son Bear with current spouse Ned Rocknroll - ended up in awe of the filming process, and has praised Woody Allen for his ''unbelievable'' female characters.

Speaking to The Hollywood Reporter's 'Awards Chatter' podcast, she said: ''He writes these very, very layered female characters that are unbelievable. I mean, just unbelievably full and rich and vulnerable and strong. It was like driving very, very fast in a really difficult-to-maneuver car with a seatbelt that kept coming unclipped.''