Sorry for your loss.
It is unlikely that mum will completely oust diamond. Goats have a very strong family dynamic. Often, a doe will take her sister or daughter with her, away from the herd, for company when she gives birth. And it is not uncommon for grandmother, mother, daughter and granddaughter and so on to all hang around together when they are all mature does. I have even seen a bottle raised doe, bottle raised from day 1, run over to her biological mother and sit down with her, when she was 12 mths old and put back into the main herd.
Depending on her personality, you might see diamond mothering the other kids. She might turn into the babysitter to give the other mums a break.