I am sex deprived. :[
...Wow, you're like the total opposite of chicks around here
They pretty much have the word SLUT tattooed to their forehead
Okay. Double standard lesson of the day.
A well-sexed girl is not a slut.
Now, if your social mores lean that way, and if you want to be a jerk, a girl (or boy) who practices unsafe sex with a large number of partners might be termed a slut.
But a girl who has a lot of safe sex with one partner at a time (or more than one, if she leans that way) is perfectly within her rights. Even if the girl changes partners rapidly, as long as she and her partners are safe, you should respect it. It might be that she's not well-adjusted, but it might also be that she's intelligent, in control, and simply has a large appetite.
And anyway, why wouldn't you term them 'players'?
(Plus, she's mostly lesbian, so as Snipes would say, it is not a target rich environment.)