Cut the turd loose. You don't need her, and it honestly doesn't sound like you've ever liked her. Seems like she's more of a friend of a friend at most. And if that's what she is, then here's what you do: start arranging hangouts, outings, and get-togethers with the people you do like. Like eating out, going to restaurants, game nights, whatever. But don't include her in them. Don't invite her, don't talk to her about them. Start solidifying among your buddies who among them is "in" the group and who are the outliers.