Hello,
How long has the lump been there for?
It is possible she could have fallen & hurt herself? A lot of times with lumps in that specific
area, an aneurism is sometimes the culprit. It could also just be some type of abscess from
an insect bite possibly or an injury.
Is she acting normally, basking & eating, etc?
You could consider taking her to the vet, for analysis. They can aspirate fluids from that area
to see if there is infection or blood present in that area.
Let us know how she is doing.
Tracie