Cheerful Katie Holmes, Suri Cruise Step Out in NYC on Tom Cruise's Birthday

USMagazine, Wednesday, July 4, 2012, 6:41am (PDT)

All eyes may have been on Tom Cruise as he celebrated his 50th birthday Tuesday in Iceland, but it was business as usual for his wife Katie Holmes and their 6-year-old daughter Suri back in New York City.

Attempting to beat the heat with a trip to a New York City ice cream shop late Tuesday, Holmes, 33, put on a brave face for her second public outing since filing to divorce Cruise on June 28.

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"Katie just looks relieved. Like she is finally relaxed and calm," a source tells Us Weekly of Holmes, who called it quits with Cruise after five years of marriage.

Accompanied by nine bodyguards, Holmes did her best to dote on young Suri, whom the insider says seems somewhat oblivious to her parents' marital strife. "Suri was her normal self, laughing and kissing Katie," reports the witness, who looked on as the tot enjoyed a sweet treat at Sundaes and Cones in NYC's East Village neighborhood. "I don't think she knows what's going on."

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Holmes also appeared in good spirits given her rough week. Confirms a second source: "Katie was smiling and seemed friendly to the staff and customers."

Despite Cruise's best intentions to have his family together on his milestone birthday -- he "begged" Holmes to come to Iceland for a last-ditch reconciliation, reports the new issue of Us Weekly -- his wife has already begun to move on.

The Jack and Jill actress secretly moved from the home the couple shared in the Big Apple to a rented pad in her own name weeks before filing for divorce. "This is about protecting her daughter," an insider confirms of Holmes' decision to flee and seek sole custody. "She wants to be in charge of how Suri is being raised and didn't want her to have an exclusively Scientology education."

Pick up the new Us Weekly, out now, for much more on Cruise's last-ditch effort to save their marriage, his "furious" reaction, why they "drifted apart," and Holmes' biggest fears for Suri.

This article originally appeared on Usmagazine.com: Cheerful Katie Holmes, Suri Cruise Step Out in NYC on Tom Cruise's Birthday