Hello and welcome to HCM
I would advice you to go for a Fine needle aspiration cytology (FNAC).
It is a quick office procedure with minimal pain and discomfort after the test.
In this test some material is taken from the swelling and on the basis of cells seen from the swelling, most propable diagnosis is given.
report indicate that the swelling is benign.
Your daughter is already on medication but swelling has not subsided. Since, there is no pain so it can be performed. without causing much discomfort.
In cases of visible swellings on body, FNAC is the best initial investigation before undergoing expensive tests like MRI.
Thanks and take care
Dr Shailja P Wahal