Tallulah Willis Attends Hotel Crillon"s Debutante Ball

From left: Rumer, Tallulah and Scout Willis
Tallulah Willis is officially a member of high society.

The youngest daughter of Bruce Willis and Demi Moore stepped out at Le Bal des Débutantes at Paris”s Hotel Crillon on Saturday night.

Willis, 17, wore a sleeveless black and silver sequined gown by Lanvin. Her hair was up and back in a chignon.

Tallulah”s sisters Rumer Willis and Scout Willis also attended the ball (but not as debutantes), and Rumer Tweeted a picture of them at the event.

Moore, who recently split from husband Ashton Kutcher, did not attend. But the girls” father accompanied them to Paris and the ball.

“He was a little different than three years ago [when Scout was a debutante], more reserved,” a source at the ball tells PEOPLE. “He was there for his daughter, but protective. It wasn”t until around midnight when he danced with Tallulah that you saw him become more relaxed.”

“He”s a dad and he wanted to be certain she felt the evening was for her,” the source added.

In total, 23 young women – daughters actors, business leaders and aristocrats – from 13 countries made their debut on Saturday night at the ball, which first launched in 1957 and re-launched 20 years ago as a charity fundraiser.

Lauren Bush, who debuted at the ball in 2000, created this year”s beneficiary, the Feed Foundation, which is dedicated to fighting malnutrition.

• Reporting by PETER MIKELBANK