Heath Ledger's sister Kate has praised Michelle Williams' parenting abilities.

The 36-year-old actress has been raising her 11-year-old daughter Matilda - whom she had with the late 'Brokeback Mountain' star - on her own since Heath died from an accidental intoxication from prescription drugs in 2008, and now Heath's sister Kate has taken the time to praise the job she's done.

Kate said: ''I think that she provides such a wonderful environment for Matilda to grow up in, especially in the sort of industry that she's in.''

And 'The Dark Knight' star's close friend Matt Amato - with whom he co-founded the music and film company The Masses - dubbed the 'Manchester By The Sea' actress as an ''incredible mother''.

He said: ''The way she's been an incredible mother, she has hero status all across the board.''

Despite Matilda only being two-years-old when Heath died at the age of 28, Kate says there are striking resemblances between her late brother and his daughter.

Speaking for the cover of People magazine ahead the upcoming Spike TV documentary 'I Am Heath Ledger', Kate said: ''When [Matilda] picks up her pencil, it reminds me of Heath; when she walks, it reminds me of Heath; when she gets on her skateboard, it reminds me of Heath.

''I tell her about her daddy every time we see each other. I tell her little stories of him growing up and how he used to chase me with the cricket bat.''

Meanwhile, Michelle previously admitted it ''won't ever be right'' to have to raise Matilda without her father.

She said: ''In all honesty, for pretty much everything else, I feel like I'm a believer in not fighting circumstances, accepting where you are and where you've been.

''In pretty much all senses but one, I would be able to go totally down that line of thinking were it not for Matilda not have her dad.

''You know, that's just that something doesn't ... I mean, it just won't ever be right.''

'I Am Heath Ledger' is set to premiere on Spike TV on May 17 following its debut at the Tribeca Film Festival on April 23.