My 1 year old daughter has been bitten by an insect (mosquito maybe), and now has a fever of 100.8 and she's breathing kind of rapidly now. any advice?

Benadryl (diphenhydramine): She may be having a mi nor allergic reaction or she may be coming down with something totally unrelated to the "bite". I'd try one dose of Benadryl (diphenhydramine) and see if symptoms subside - then likely allergic. Otherwise, she may be breathing a bit fast because she has a low grade fever. It's a baby/toddler way of trying to cool themselves down a little - kind of like a dog panting in the heat. Give fluids.