Parenting advice..??

Hey everyone! I'm in need of advice from the mommies/blended families out there!

My boyfriend and I have been together for 6mo, he has a 3 year old daughter. She does see her mom, but doesn't like spending time with her. Recently she has been saying she doesn't have a mommy and wants one.

I'm kind of lost as to what needs to be done, if anything, considering I don't have children of my own.

-Thanks!