My Daughter Was Stung By A Bee 3 Days Ago.

My daughter was stung by a bee 3 days ago. The sight is still very red and is not getting any better. The redness in fact seems to be getting worse. However it is only slightly swollen.... She is taking Benadryl and I am putting antibacterial cream to avoid infection. Should I be worried about a allergic reaction or infection? Tomorrow will be day 4 and not seeing any signs of improvement.
Also the sting was on the arm. She is breathing fine, eating ect. The only thing she has complained of is itching.