The mom of two recreated a seductive photo shoot while pumping, something McAdams did for Girls, Girls, Girls Magazine earlier this month.
In the black and white picture, the former Disney star is seen exposing her left breast while hooked up to her pump. "Am I doing this right?" Hilary wrote.
Wearing her shower cap and a button-down shirt, Hilary gives her best smize while posing straight on for the camera. Sharing her picture, along with McAdams, both moms look like a force to be reckoned with.
As The Blast reported, Hilary just gave birth to a little girl named Banks in October.
This is her first child with boyfriend Matthew Koma. She's also mom to her six-year-old son, Luca Cruz, whom she shares with her ex Mike Comrie.