Lindsay Lohan has been "doing great" since she checked into rehab over Memorial Day weekend, her mother says.

"I talk to her every day," Dina Lohan told PEOPLE in New York on Monday. "She's going to do Promises' extended care program."

The program, according to Promises' Web site, is designed to help people "make the transition from residential alcohol or drug rehab treatment back into their community." It includes a 12-step program and group therapy.

Dina also said she and her family will head west for Lindsay's 21st birthday on July 2. She didn't say where the celebration will be held – a previously scheduled party in Las Vegas was canceled – but her security guard Ty Dux said, "It won't be on the Promises premises."

Dina Lohan was appearing in Nassau County family court as she awaited a hearing in her ongoing dispute over visitation of her children with ex-husband Michael, who was also in court.

"I just want to move on," said Dina, who has an order of protection against Michael. "It takes its toll on myself and the children. It affects all of us."

Michael was released from prison in March after a 25-month lockup for charges that included DUI and assaulting his brother-in-law. Asked on Monday if she were afraid of Michael, Dina Lohan answered, "Yes."