Question about tgirl names from Brazil

[Dinand]

I'm keeping a database but I'm wondering about the spelling for these names:

Patricia Bysmark or Patricia Bismark?
Mylena Bysmark or Mylena Bismark?
Thais Schiavinato or Thays Schiavinato?

[Fox]

The letters I and Y seem to be very interchangable in Portugese, but it looks to be two sides of the same coin separated by liguinstic customs. Example, in English someone's name could be Michael; in Spanish, Miguel; in French, Michele (or something like that).

I don't think it really matters, but it can make it a little annoying if you're searching for a particular cutie. =P

[Dinand]

I googled those names and even then I couldn't find the answer.