Hi, welcome to HCM, I am Dr. Das
Firstly, a lymphoma
never cause painful lymphadenitis
. When there is non tender lymphadenopathy
for many months then we suspect lymphoma with p[resence of other signs and symptoms. It is said that common diseases are diagnosed commonly and rares are rarely. So concentrate on common disease.
From the history , it is evident that she has an infection of tonsil- tonsilitis
which is acute. This leads to painful enlargement of lymph nodes.
So, first consult with doctor to have some antibiotics which causes decrease in inthe infection and if even after the course of antibiotic the lymphadenopathy persist then it should be reviewed.