16month old started Bactrim (sulfamethoxazole and trimethoprim) 2 nights ago for a skin infection that might be MRSA. She had a fever last night and this morning 100.8 (armpit). ..normal?

Re-evaluate... Follow up with your daughter's physician today and let them know that she has developed a fever after being on the antibiotics for two day. They will want to see the area of infection and make sure that it isn't the cause and that the antibiotics don't need to be changed. The fever could be from an unrelated viral illness, but you won't know until she is examined.