Even when they flop to the sides when laying down on her back? (Asking for a friend)
This happens to some people with implants too! I know it does in my case. Mine also feel impressively close to the real thing according to a lot of people, but I guess this could all be due to the fact I already had a good amount of natural breast tissue before getting implants (and I suspect my boobs got bigger too the last couple years lol)