The 34-year-old star, who is expecting her first child with fiance Brian Hallisay early next month, was joined by 24 of her closest friends and female relatives for the lavish event in a private room of a hotel in LA, reported E! online.
"There were flowers galore and about two dozen guests. It was a very girly affair," a source said.
The 'Ghost Whisperer' star previously said she is delighted to be expecting her first child as she always wanted to be a mother.