"Who is she?"
Translation:Pwy ydy hi?
You do not say what kind of question it is, but either of Pyw yw hi? or Pwy ydy hi? can be used as a translation here, and either one might be suggested as a correction to an incorrect translation.
If it was a tiles question, the available tiles should allow one of those to be put together. If it was a 'type what you hear', only the one that is actually spoken will be accepted.