Celebrity Celebrity Moms Pink's Daughter Celebrates Baby Brother with "Big Sister Party" By Lara Walsh Lara Walsh Lara Walsh is a Chicago-based writer and editor who covers all things fashion, celebrity, pop culture, travel, and food. When she’s not avidly planning her next trip, she’s writing posts for her travel blog or mapping out her next foodie adventure. InStyle's editorial guidelines Updated on January 16, 2017 @ 03:00PM Pin Share Tweet Email Photo: Tommaso Boddi/WireImage It looks like Pink's 5-year-old daughter Willow is completely smitten with her younger brother. The Hart family welcomed their newest addition, Jameson Moon, in late December, and big sis Willow couldn't have looked happier ringing in the new year cradling the sleeping infant in her arms. Now the pink-maned toddler is officially celebrating her initiation into the big sisters club with an adorable "big sister party" complete with chocolate cake, balloons—and her little brother, of course! Pink took to Instagram to document the celebration on Saturday, sharing an adorable photo that shows her oldest child holding a chocolate cake decorated with a pink bird and the words "Congrats big sis!" while mom holds a swaddled sleeping baby Jameson. Green and pink balloons decorate the background. Instagram/pink "Congrats Big Sis! #bigsisterparty," the 37-year-old proud mom captioned the sweet shot. Pink's Daughter Rocks Pink Hair as She Holds Her Baby Brother Could this family get any cuter?