The 'My Week with Marilyn' actress has nine-year-old Matilda with late actor Heath Ledger - who died of an accidental overdose seven years ago - and the 'Dark Knight' star's sister Kate Ledger is impressed with how she is raising the little girl.
She said: "[Matilda is an] expressive, creative, beautiful girl who is fortunate enough to have great grounding from her mum.
"Michelle really does keep things real for her, and her existence, although different from most, is as normal as possible in an abnormal world."
Meanwhile, Kate loves to bond with Matilda by telling her stories of the 'Imaginarium of Doctor Parnassus' star's upbringing in Perth, Western Australia.
She told Australia's Daily Telegraph newspaper: "I love telling [Matilda] stories about her daddy and how he grew up.
"I think it's so important for her to have a good sense of where she comes from in order for her to get to know herself."
Despite her brother's success, Kate says he initially struggled making the transition from his home town to Hollywood.
She recalled: "He spent a lot of time on peoples' couches, eating packet noodles with little money.
"He knew no one, had nothing and had to fight to survive. Of course, like most actors, maintaining integrity in the roles you accept or choose is also a struggle.
"For Heath it was of paramount importance."