My 3 yr old, finished antibiotic for tonsillitis 2 days ago. since last night she has temp with a stuffed nose, calpol is helping, is this related?

Fever: Most probably she got penicillin/amoxicillin for tonsillitis (if not allergic to) which takes care of tonsilitis. Fever with stuffy nose is usually caused by viral illness. Give fever med. Only when temp. Is 101 f or above. Make sure she drinks enough fluid. Can give otc diphenhydramine/benadryl for congestion. If not better in 5-7 days, make a folow up visit with her pediatrician.