Daughter is 2.3 years old. Still not talking properly. Only mama papa,…

Daughter is 2.3 years old. Still not talking properly. Only mama papa, boom boom, gav gav. And that's it. She understands spoken language. She explains things with sounds, squeaks, and gestures. We don't go to daycare. Lives only with mom and dad. Doesn't like playing with children. But loves to watch them. And yes, still in diapers? What do I do?? We have problems with potty training, she doesn't want to go anywhere. What about kids who talk late?