I am sure Meriam Webster has a more stringent procedure for the modification of defintions, but regardless - I beleive, and it seems clear from this thread even, that this girls behavior fits the bill.
I understand people are sensitive to labels / names that are perceived as degrading, but that doesn't make them any less applicable.
I think that men that go around bang bang banging everything every chance they get are disgusting - I don't see how they enjoy it and I think they are quite literally dirty. The same applies to women, but additionaly - as proven in this case - women have additonal burden when it comes to sex, especially of the unprotected variety. Like it or not, their bodies become impregnated and with that comes responsibility.
Further - I think it's especially whorish and deplorable to fuck someone else's husband. I have very little sympathy for this girl and as many have pointed out it's likely a scam. If she were asking me for money I'd be making damn sure I wasn't being scammed before I did so, but in the end if it was my child I'd absolutley take care of my responsibilities.