Hard to believe, but Michelle Williams' little girl, Matilda, is now 5. And the 'Blue Valentine' star knows the day will come when her daughter will want to learn about the acting legacy of her late father, Heath Ledger -- and about the two co-stars who became her parents.

In a new interview with Angeleno magazine (via People.com), Williams talks humbly about her Oscar-nominated work portraying the wife of Ennis Del Mar (Ledger) in 2005's 'Brokeback Mountain,' and acknowledges that the film will always be meaningful in her life as a mom.

"I was just an actor who happened to be lucky enough to be in the right place, and it was the place where I met Matilda's father, and that is a lot," she says of first working with Ledger, who died of an accidental drug overdose in January 2008. "And it will be a lot for Matilda too, when she gets around to watching it. I will watch it with her, when she's ready. It is hard to imagine what that would feel like, but one day, yes, we will watch it together."