Tallulah Willis Celebrates Her 18th Birthday

02/04/2012 at 12:45 PM EST

Life goes on!

As mom Demi Moore seeks treatment, daughter Tallulah celebrated her 18th birthday with a bash on Friday.

The party took place at dad Bruce Willis's Beverly Hills mansion, and it started in the late afternoon. Tallulah wore a tiara and appeared to be in good spirits.

Joining her: her sister Rumer and Bruce's pregnant wife, Emma, who was spotted hugging the birthday girl several times.

RELATED: Demi Moore Is in a Treatment Facility: Source

Moore, meanwhile, has not been spotted since news of her health crisis broke. A source close to the actress says only a "very close" group of friends knows where she is. Says an insider: "Demi is such a private person and where she is now is being kept top secret."