Best known for her role in teen angst TV show "Dawson's Creek," the actress has been at the center of recent reports claiming she is snubbing her husband's last complete film because of a dispute with Ledger's family over the handling of his estate.
But the star's representative Mara Buxbaum is keen to put the rumors to rest once and for all, insisting the actress is not feuding with the Ledgers - and insisting Williams never intended to walk the premiere's red carpet.
She says, "There is misinformation all over the place. (The premiere) was never on her calendar and she's not in the movie. This isn't a press event for her. She's not going, there is no reason."
Ledger's parents and sister are expected to jet to New York from their home in Perth, Australia, to attend the premiere on July 14 - six months after Ledger took an accidental overdose at his Manhattan apartment.