Jessica Alba admits she is still a ''real prude.''

The 'Sin City: A Dame To Kill For' actress - who reprises her role as stripper Nancy Callahan in the sequel - insists that, despite being cast in a number of sexy roles, she is nothing like her characters in real life.

She said: ''The key word is play - everyone who knows me well knows that I'm a real prude. But a good director can make a scene look sexy without me taking off my top.''

The 33-year-old actress - who has children Honor, six, and Haven, two, with husband Cash Warren - also insists she isn't perfect and finds it a challenge to juggle her busy career and motherhood but thinks it is important to be a good role model for her daughters by doing both.

She added in an interview with America's OK! magazine: ''I'm very lucky I have a lot of help. As women, we have to accept that we can't do it all. It's important to show our daughters that there's more to each of us than just being a mother.''