Burrfish update and really need advice!

[GreenSpottedPuffer]

Im really not convinced she has IP either. I think she is just very under weight. How long would it typically take for a fish like this to put weight back on? I kow Burrfish usually have smallish bellies anyways, unlike other species of puffers.

Im worried Im putting her through stress for no reason.

I really want to get her in the display tank soon but I don't want to expose my other puffer to anything bad. How are IP picked up? Is it something the other puffer could get easily if she did infact have them?