Getting your adoptive child to call you mom

I don't know how long they have been in fc or how long they were with their previous fm, but I do know that three weeks is not a long time for the girls to FEEL you are their mom. We had our kids for a year, when my older kids asked what I wanted for my birthday. I told them that all I wanted was for them to call me "mom" (we had permanency with them by that time). I told them that I love them and I know I AM their mom, but the best present I could ever get would be for them to acknowledge I'm their mother by calling me mom. I also told them the whether they called me Mom or Riley didn't make a difference with how I felt about them, they were still MY kids! I DID get my birthday gift! And it was wonderful, bc although I had to ask for it, I knew it was from their heart. It means so much more for me to hear them call me mom bc I know that they FEEL I am their mom! Do you have other children? My younger kids started calling me mom right away, but they also had RAD and heard my bios calling me mom. Give the kids time. They've been through a lot with all these moves. They need time to process everything. Also, you may want to start attachment therapy to help them with bonding. Spend lots of time with them in the meantime. Congratulations.