06/16/2008 at 01:00 AM EDT
At the opening of the Palms Place hotel in Las Vegas on May 31, Sarah Larson spent the night laughing with pals, enjoying vodka cocktails and dancing in the party's VIP area. Her solo outing—the first since her split with beau George Clooney
was made public three days earlier—contained no indication that Larson is, according to a close friend, "going through a really difficult time." Says an observer at the event: "If she was upset, she was hiding it well. She put on a brave face."
Larson's spunk—she once famously ate a scorpion as a Fear Factor
contestant—is one of the things that attracted one of America's most eligible bachelors to the cocktail waitress turned model. Clooney, 47, and Larson, 29, first met in Las Vegas about four years ago, but it wasn't until they reconnected again last June that sparks flew. While the couple gave no reason for the split, Larson's friends say it was something the pair had discussed. "They'd talked about it before, but she was pretty shocked when it happened," says a pal. "She didn't think they'd necessarily get married, but she thought it was the real deal and they'd be in it for the long haul."
That certainly seemed to be the case last fall. After a few early bumps—namely, the motorcycle accident that left Larson hobbling on crutches—their romance blossomed. "He's just laid-back, really a normal guy," Larson told PEOPLE in March. When asked if he was a good boyfriend, she said coyly, "I have no complaints."
Since the split, Clooney doesn't seem to be licking his wounds. He enjoyed a weekend with the guys in Puerto Vallarta last month—"He was smiling and seemed to be having a great time," says an observer—and is now summering in Italy. Larson, meanwhile, is "100 percent focusing on work," says Kenya Knight, her agent at Nous Model Management. Says a pal: "She's such a strong, independent woman—that's what George liked about her. She's going to be fine."