What breed are the rest Scotsgirl? Goats are racist (seems weird I know, but we have definitely had cases of racism here), so it could be the breed, but also just that she is bottom of the heap as it were.
If you are leaving the kids on the mums, I would separate out the mums in advance by a week or so if possible, before they kid, and if not, when they do kid, I would separate them with their kids for 2-3 days at least to let her and the kids bond. Same as you might do with sheep really. The other mums shouldn't beat up another goats kids, not if mum is around !
Beth