Inside Hilary Duff's Baby Shower

Lizzie McGuire is all grown up!

On Sunday, Hilary Duff was feted by family and friends at a baby shower hosted by her older sister Haylie and their mother, Susan. "What an amazing day!" Hilary tweeted. "This baby is spoiled already! And this mama is wiped out!"

PHOTOS: Hilary Duff: Then and now

The 24-year-old singer and actress, who's expecting a baby boy with her husband, Mike Comrie, was joined by pals Beverley Mitchell, Sophia Rossi, Erin Haggerty, Beau Nelson, Lauren Anderson and Marcus Francis.

A source tells Us Weekly that the shower took place at Duff's house in Los Angeles with "40-50 people, small and intimate."

PHOTOS: Other stars who romanced athletes

Haylie, 26, tweeted several photos from the low-key soiree, including one of herself with Hilary and a bib that read: "My aunt is hot and single!"

Once the festivities were over, Hilary expressed her gratitude via Twitter.

PHOTOS: Baby bump hall of fame

"So grateful for all my friends and family that love and support me through all these huge milestones in my life!" Hilary wrote Sunday. "Such special memories today!"

The baby boy will be the first child for Duff and Comrie, 31, who wed on Aug. 14, 2010, in Santa Barbara, Calif.

MORE FROM WONDERWALL:

Hilary Duff's Bright and Trendy Maternity Style

2012's Celeb Baby Brigade

Celebs in the Holiday Spirit