Williams, who is currently filming a new movie about Marilyn Monroe in the UK, also told Australia's Madison magazine she had to admit she needed help to be a successful working mum to Matilda, five.
Talking about visiting Ledger's family, she said: “I return to Perth as often as I can to visit. There is a lot of mobility between Matilda and I and her family are from Australia.”
She called the flight “brutal” but added: “It’s always worth it. I mean, what I wouldn’t give to go back to Byron Bay. The Margaret River is gorgeous, too.”
Williams, 30, said the balance between work and motherhood wasn’t easy. “That answer didn’t come quickly for me. Admitting that I needed help. I tried to do it all on my own.”