Filming of Michelle Williams's next movie, Blue Valentine, has been put on hold while the actress copes with the death of Heath Ledger, a source tells PEOPLE.

"We will hold off until she is ready," says a source connected with the film. "The production is in the process of sorting it out in respect to her."

The movie – a relationship drama centered around a young couple struggling with their marriage – also stars Ryan Gosling, who Williams was rumored to be dating after they were spotted strolling together in New York before the holidays.

Production on the film was set to start on February 25, but has been moved back to an indefinite date.

"We're hoping she will still come back and do the film and are happy to wait," the source says. "The film is tailor made for those two so of course we would want to wait. You can't get much better than them."

Williams had just finished shooting her last scene in the film "Mammuth" in Sweden when she received the news of Ledger's death.
[source]