Teething does not generally give fevers that high. I would get her throat and ears checked again with a temp of 40+ and pain / distress on sucking or swallowing. Particularly after 3 days. Even if she is drinking well.

Febrile convulsions occur through rapid changes in temperature, not the actual height and only in those children who are sensitive to the changes (family history is one indicator) At 16 months they feed for many reasons so there is no reason to expect she will wean. It just sounds like it hurts her ATM.