Rumer Willis
Rumer Willis will be guest starring in season 4 of "Pretty Little Liars." REUTERS/Fred Prouser

Rumer Willis didn't want to miss out on the SAG 2012 celebrations and so she reportedly snuck into the official after party over the weekend.

According to Us Weekly, the 23-year-old actress was a part of the official after party for the Screen Actors' Guild Awards that was held in a tent outside the Shrine Auditorium in Los Angeles.

An observer told the celebrity mag that Rumer Willis kept a low profile and that she didn't want anyone at to see her.

Rumer was like an apparition -- she just slipped in with a friend and then was gone, a SAG 2012 partygoer told Us Weekly. She looked like she was walking on eggshells...She was just weaving through the crowd.

Rumer Willis' mother Demi Moore was hospitalized last week, after experience seizure-like symptoms and falling semi-unconscious. Reports were that the 49-year-old actress inhaled nitrous oxide or did whip-its.

Us Weekly reported that speculations are that Rumer Willis was among those who were present at Moore's home last Monday when the shocking 911 was made. Moore suffered convulsions after she smoked something, a female caller told the emergency dispatcher.

Moore's camp issued a statement after her hospitalization noting that she decided to get professional treatment for exhaustion.