05/31/2007 AT 08:00 AM EDT
Maybe the second time's the charm for Lindsay Lohan
, who a friend says is settling well into her rehab treatment
"She's happy where she is and is just taking time to herself to learn and be okay," stylist friend Nate Newell told PEOPLE at Wednesday's Los Angeles opening of the flagship Diesel store on Melrose Place. "I've been in touch with her and she likes it."
After a weekend of partying
following her DUI citation
, Lohan checked into Promises treatment center in Malibu on Memorial Day.
"She's so much in the public eye 24 hours a day that she's gotten so caught up," Newell explained of the factors contributing to Lohan's ongoing struggle. "I think she surrounds herself with good people generally, but all the pressure that she's around has created this alternate universe in a way and it's hard for her to stay grounded."
Although Lohan, 20, had checked into
the Wonderland Center in West Hollywood in January, her continued partying after her month-long stay only intensified suspicions of substance abuse.
During her stay at Wonderland, "she was back and forth from the I Know Who Killed Me
set, but this time she'll totally be there [at Promises]," said Newell, who plans to visit the actress over the weekend. "She just needs to be away from everyone and not get attacked by the paparazzi."
Lohan was able to leave Wonderland due to its program called Sober Companions in which patients may leave the center, accompanied by a staff member, for pressing work commitments or to visit children and family.
"She's doing really, really well," he added. "She probably should be there and it will be the best for her. I think [now] she's ready for it."
Lohan's next movie, Poor Things,
was slated to begin filming on Thursday in Los Angeles, and at the actress's request, the project will find a way to ensure her continued involvement.
"We are trying to rearrange the shooting schedule to facilitate her working at the end of the shoot to coincide with the completion of her rehabilitation," producers Rob Hickman and Shirley MacLaine said Wednesday
"We wish her love and the blending of mind, body, and spirit."
Meanwhile, Lohan's most recent hookup
, Calum Best, was also at the Diesel event, and told PEOPLE, "I support her 100 percent."
But Best, 26, has his own troubles: The British TV personality recently told U.K. newspaper The Sun
he's a sex addict with a drinking and drug problem. "I'm a bad boy," he said. "I go out and get drunk, I get high on cocaine and I do stupid debauched things with the wrong women."
As for Lohan, he said: "Lindsay needs to concentrate on herself now. If she's having problems I will back her up. She is a lovely girl. I'm here to support her. I can't say she's my girlfriend. We'll see. We're still in touch."