would you not agree that:Krysia = KrystynaKasia = Katarzyna
that's right, but some girls don't like these diminutives as sounding too childish and prefer augmentative forms: Kacha, Krycha, Gocha.
Someone pretending to be a Pole Might use Krecha.
No, actually, it could be a perfectly good Polish nickname.
The name Pygota doesn't show on the map of Polish names, nor in Google in general.
It should be possible to find the gallery where she works and check if she's really working there, or even confirm that she really writes to you.
Still, assuming that she's a real person, there is an ethical question. Andy, would you be willing to provide her with the same kind of information and be subject to the same kind of check-up?