06/03/2007 at 02:45 PM EDT
isn't letting her impending jail time
get her down.
On Thursday, Hilton – who has until Tuesday to begin serving a minimum of 23 days
for violating probation – and sister Nicky hit an L.A. party at the Regent Beverly Wilshire Hotel, where she was "laughing and living it up," an eyewitness says. Afterward, the siblings made a brief appearance at a pre-MTV party at a Beverly Hills mansion.
The following night, Hilton was spotted at Hollywood hot spot Les Deux, where she arrived, clad in a skin-colored chiffon dress, around 11:45 p.m. with a sizable entourage that included her sister Nicky and Nicky's boyfriend David Katzenberg.
"Paris seemed very composed, but certainly was not the crazy party girl from recent nights out," says one clubgoer.
The 26-year-old heiress briefly emerged on Saturday afternoon from her Hollywood Hills home to an awaiting mob of photographers camped outside. Wearing a yellow sunhat and tropical-print sundress with her hair in pigtails, she was chauffeured by a black stretch limo Escalade to a nearby Coffee Bean and Tea Leaf, ordered an iced latte, then promptly returned home.
"She looked gorgeous and seemed in high spirits," says an onlooker. "She was smiling and playing coy with the paparazzi."
Early that evening, she picked up mom Kathy and sister Nicky, and together they headed to Kathy's 30-year University High School reunion at the Hotel Sheraton Delfina in Santa Monica, followed by dinner at Mr. Chow.
As the clock struck midnight, the sisters parted ways with Mom and, with a male friend and Katzenberg, hit the Hollywood hot spot Teddy's, where Vince Vaughn and Michael Vartan also made appearances. After about half an hour, they took the party to AREA.
"Paris was in a great mood," says a fellow clubgoer. "It was like a normal night out with friends. You wouldn't know she's about to go to the slammer."
Meanwhile, media have begun staking out the Century Regional Detention Facility in Lynwood, Calif., where Hilton is to do her time.
But Sheriff Lee Baca, whose department oversees the jail, told the Los Angeles Times
on Saturday that authorities will not allow Hilton to "be seen in handcuffs ... or in the back of a police car, forlorn and in handcuffs."
"Jails are not circuses and not places where 'fun' is the priority," Baca said. "Jail should be a corrective learning experience."
Reporting by JENNIFER GARCIA and LYCIA NAFF