Not liking the assumption being made in the scenario that Dumbledore always comes and tells muggle-borns that they're magical.
He was a busy man and all...
Nice touch with the parseltongue by the way, although unless the girl turns out to be a powerful dark wizard would seem to be very unlikely. Parseltongues are very rare, so having two born (Harry, + character) within ten years is pretty interesting. If it's not overdone it could work well.