Friday's news that Katie Holmes and Tom Cruise were divorcing after five years of marriage came as a shock to some, but a source tells Us Weekly that the signs have been there.

One telltale sign was Holmes' increasingly happier demeanor. "She's been miserable for a long time, but the last couple of weeks, she's been happy — like she's been set free," the source tells Us.

Indeed, just one week ago, the 33-year-old actress and the couple's 6-year-old daughter, Suri, enjoyed a day out in NYC on June 24. The smiling mommy-daughter duo sported coordinating black-and-white ensembles and stopped at their favorite spots Serendipity 3 and the American Girl Store.

"I was wondering what changed with her," the source adds. "I guess she can finally be happy again."

With Cruise, 49, away filming the sci-fi flick Oblivion in Iceland, Holmes quietly filed divorce papers with the aid of a New Jersey-based attorney, and requested sole custody of the couple's daughter. To ensure that Suri would have a stable home base, the actress had secretly rented an NYC apartment of her own just prior to filing for divorce, Us learned exclusively on Friday.

"Katie's primary concern remains, as it always has been, her daughter's best interest. This is a personal and private matter for Katie and her family," Holmes' lawyer, Jonathan Wolfe, said in a statement to Us Friday.

Through his rep, Cruise said he was "deeply saddened" to hear of Holmes' divorce filing.