If all the meds that mom was said to be taking are ruled out as cause of
nursing strike, perhaps you could try to focus on the teething issue.
Four teeth at once, possibly the cause of the low-grade fever
incidentally, could be the root cause of this problem. Have mom
"anesthetize" baby's gums with frozen teething ring or even rub ice
cube on gums, make a game of it, then try to get baby to nurse. If she
pulls off and screams again, repeat the ice-rub. My kids went berserk
when teething, so my sympathies to the mom.

Good luck. Judy Knopf