Hello, I am wondering if I could get some insight in what could possibly be going on with my tree frog.

I have a male and female who live together, and have been together for a little over a year. Just recently I discovered this lump on the backside of my female. It is soft and has no hard mass when I touch it, and doesn't seem the bother the frog when touched. Her behavior has not changed either.
I have researched a little about it, and came up with parasites, cysts, abysses, but none of the pictures posted really look like hers, so I am wondering if anyone here could shed some light on what this could be.

Their tank stays clean, and she doesn't appear to have injured herself in anyway. I was planning on taking her to a vet if I didn't see a change, but I would love if I was missing something, and could help her myself.

any advice would be appreciated.