Before she takes her foray into marriage, the Private Practice star grabbed a group of girls, including former Grey's Anatomy castmate Sara Ramirez, and headed to Sin City for the pre-nuptial rite of passage.
And the girls lived it up with sunning, workouts and even some "male entertainment," all of which was arranged by Las Vegas party planner Mike Doty, PEOPLE has learned. (Doty declined to comment for this story.)
Kicking off the festivities Friday night, the party laid low, gambling a bit at The Venetian – then resting up for Saturday.
Walsh and company began their wild day by sunning at a private cabana at Tao Beach. "They were really relaxed and having fun, but a few of the girls, including Kate, left when it got busy there."
After a quick workout, the actress then got a surprise in her hotel room: a visit from two male strippers.
Later, continuing their Vegas blitz, the ladies were spotted dining on sushi rolls, lobster wontons and Kobe beef at Tao Restaurant. "You could tell they were all really content. Kate looked really happy and couldn't stop smiling," an onlooker said.
"Sara (Ramirez) even got on the table and started dancing," the source said. "Everyone was laughing and clapping."
Following dinner, the party of 17 headed up to Tao Nightclub, where Walsh drank lightly and eventually joined Ramirez on the club's catwalk, dancing until 1:30 a.m.
"I know – I'm literally living the dream," she said of meeting her fiancé just three months earlier. "But you know when you know. I was not expecting it, so it's kind of amazing."