As you have no doubt seen, it is speculated on NTP that it could be one of either Heather Christensen or Heather Carolin but I can't be sure of either, and neither can they.
Someone did actually confidently answer it as Heather Christensen in another topic on there but I think there's a reason it didn't get any support or marked as the answer.
Anyway, this is why it's worth extra points on there... because seemingly nobody can come up with the answer.