@hilaryduff / Instagram 1 / 10
@hilaryduff / Instagram 1 / 10

Can Hilary Duff plan our next event?!

The 27-year-old "Younger" actress and her mother Susan planned a gorgeous, star-studded baby shower for her older sister -- 30-year-old "Napoleon Dynamite" star Haylie Duff -- last Saturday, March 7, which was the stuff of Pinterest dreams.

Held at Hilary's home, guests included Kaley Cuoco, Lauren Conrad, Jenna Dewan Tatum, Lacy Chabert, Marla Sokoloff, Beverley Mitchell and Ali Fedotowsky.

In December, Haylie announced she and fiancé Matt Rosenberg are expecting a baby girl.

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"Sissy @haylieduff you are the most beautiful sister/mom to be and I love you so much!" Hilary posted on Instagram on Sunday, alongside an adorable slideshow of photos from the happy event. "Happy baby shower day!"

Activities at the baby shower included guests making their own flower crowns with fresh flowers, assembling bouquets by The Bouqs and enjoying lots of sweets like mini cupcakes, cake pops and macarons.

"Had the best day celebrating our baby! #MHbabylove #babyshower," Haylie Instagrammed.

Clearly, her guests enjoyed the festivities as well.

"Spent the day with some amazing friends, flower crowns, babies, bunnies, champagne, cake pops all in honor of the gorgeous mommy to be @haylieduff 😍," Cuoco wrote alongside this sweet group selfie.

"Had the best afternoon showering the gorgeous mama to be @haylieduff and her little lady! 💗 #MHbabylove," Dude, Where's My Car? actress Sokoloff also posted.

Haylie and Matt announced their engagement last April 3.

"Entering this new chapter of our lives and our relationship has been so special," Haylie told her fans in December in a post to her food blog Real Girl's Kitchen. "We are so happy and so in love with her already!"