Hi.. Can understand your concern.. As per your complain it seems that your daughter had a deeply infected tooth with nerves and blood vessels exposed. If a filling is done in such a tooth there leads to swelling due to inflammation and locking of infection inside leading to pus formation.. In such a case you should consult your dentist back and get an x ray of the filled tooth done to rule out the cause of swelling.. In case of deeper filling is the cause removal of the swelling followed by root canal treatment and antibiotics and painkiller will solve the issue. Hope your query is solved.. If you find the answer helpful please write a positive review and click on find this answer helpful as a token of appreciation.. Thanks and regards.. Dr.Honey Nandwani Arora.