People

Lindsay Lohan Photo by: Janet Mayer / Splash News

Less than a month after entering rehab, Lindsay Lohan is "doing great," her mother tells PEOPLE.

"She's amazing. She's great and she's happy," Dina Lohan said Friday at the Child magazine fall 2007 fashion show in New York City. "She's in a really good space right now."

Lohan, 20, checked into rehab at the Wonderland Center in Los Angeles on Jan. 17, calling the move "a proactive decision to take care of my personal health."

In December, she had revealed that she had been attending Alcoholic Anonymous, and later that month told PEOPLE, "I feel better not drinking. It's more fun."

Of her daughter's treatment facility, Dina Lohan said Friday: "It's wonderful at Wonderland – how cheesy."

Late last month Lohan went back to work on her thriller I Know Who Killed Me.