Getting your adoptive child to call you mom

We're on day 8 with S., so we're right at the beginning. But here's what the CW, who's also an adoptive mom, advised us. To S., her former foster parents are Mommy and Daddy. And she knows that she has another Mommy as well who she doesn't see anymore. Her CW has us call her former foster parents Mommy "firstname" and Daddy "first name". I don't correct her when she calls them that, but when I refer to them I use the same thing. Her CW calls us Mommy Allana and Daddy Martin, though S. has been very clear that she will be calling us Allana and Martin for now. And that's fine. We will eventually phase out the Mommy and call them Auntie and Uncle. When our parents talk to her, they call us Mommy and Daddy, and she accepts that.