The bizarre thing...is her behavior. She can right herself, still swims about rather actively, can ascend and descend the water column fine, and doesn't appear to be bothered. I haven't offered food because I've been afraid of intestinal blockage... The thing that's weird is she's no longer so skittish. She's normally a fish who hides 90% of the time for whatever reason and I typically leave her be, which is probably why I didn't see this today. But part of the reason I saw her today was because she didn't immediately flee and hasn't panicked nearly as much in my presence as I'm used to her panicking. She doesn't appear to be respiring very hard...
Her scales aren't standing on end, I don't see any wounds, ulcers, fungus, or external parasites. The other fish seem to be fine (Corydoras cats, a couple of ottos, and one other much younger female three spot). I put on a pair of gloves and covered them in stress coat to see if she'd let me touch her. I quickly and gently palpated the mass and it feels soft, not hard. I put the lid on her hospital container to leave her be...she's only four years old, I thought she had at least another two in her?
What do you all think this is? What should I do?