If you mean the slut with three eyes, yes. She is a prime example of an Alpha Bitch that tries to climb up on the social ladder at the cost of the weaker ones and especially Willow. And i can't see her recieving a redemption arc like Amity got one. She's just your classical bullying Alpha Bitch.
I’m guessing a lot of people think Rei is the “Alpha Bitch” because of her attitude. She’s more of a tsundere. Although she can be quite mean to Usagi and even Yuichiro at times, she means well and doesn’t intentionally try to ruin others lives like an Alpha Bitch would.