Michelle Williams doesn't smoke in front of daughter

Michelle Williams refused to smoke in every scene when filming My Week With Marilyn because she didn’t want to set  a bad example to her daughter.

The 31-year-old Oscar-nominated star bleached her hair and piled on the pounds to play Marilyn Monroe.

But she didn’t want six-year-old Matilda her daughter by late Dark Knight star Heath Ledger to see her puffing on cigarettes.

“Michelle smoked as little as she could even though Marilyn smoked a lot,” a source said.

“Michelle used to smoke but is now fiercely against it and didn’t want to set a bad example to her daughter. It upset her when Heath was alive that he chain-smoked and she is obsessed with avoiding any bad habits that could affect Matilda.”