Party of three, please!  Actress Lacey Chabert is pregnant with her first child!

The Mean Girls actress made the announcement by sharing a photo on her Instagram page showing her dog wearing a shirt with the caption “My mom is having a baby & all I get is this silly shirt.”  Chabert added, “Kitty doesn’t seem as excited as we are about this…I’m pregnant!!!! My husband and I are thrilled and so thankful.”

The actress is best known for her roles as Claudia Salinger in the TV series Party of Five and as lovable airhead Gretchen Wieners in the film Mean Girls.

This will be the first child for Chabert and her husband Dave Nehdar; the couple married in a surprise ceremony on December 22, 2013.