Lindsay quietly celebrates 21st birthday

Happy birthday Lindsay Lohan! The rehabbing starlet is quietly celebrating her 21st birthday with family in LA rather than in the previously-planned Vegas blowout. Lohan's mom and siblings were seen arriving at LAX over the weekend for a family party, and the Georgia Rule star was spotted going for a birthday jog on the beach this morning. Lohan has made a few recent outings from the Promises facility in Malibu, stopping by Planet Blue with a brand-new iPhone in hand on Saturday and drinking tea, diet coke and water on Friday at the Chateau Marmont. Last Wednesday, Lohan headed out for sushi with friends after attending an AA meeting in Santa Monica. "She came in with a whole bunch of friends, there were like seven of them, and she walked in incognito, super low-key," said a fellow diner at Katsuya in Brentwood. "They sat down for some sushi and were just really enjoying themselves. She wasn't really noticed at all and was just happy, in a good mood."