It sounds like your phal went into shock and produced a baby to save itself. Don't be surprised if the mother plant dries out totally and dies.
This is why I only grow orchids in windows that have sheer curtains on them to diffuse the direct sun even in the winter.

If this is your only window, you also can diffuse the light with bubble wrap between the glass and the orchid. It also helps to put aluminum foil on the sunny side of the pot. I hope your plant recovers. J