...?[] She's a hollow with a disguise power. It fails when she's hurt.
This is probable the worst option here. They are probably going to want to test this power by hurting her, you guys know that right. I can just see someone going ... well how much damage can she take before it fails and then you are in trouble because you lied.
It's not like most hollows have high speed regeneration. All Tatsuki needs to do is cut herself and out bubbles the strangely hollow-like white goop. That would be the disguise failing.
It's not like they're going to lop of a limb, or anything.