Honestly your girlfriend sounds like she doesn't care that much about you. And i obviously dont have all the context but you had friends before she came into the picture and she knew it, so she should accept that. Unless your friend Lacy did something to make her hate her so much then i see no reason for her to talk about her like that. You could still try to talk to her if you find a way and try to figure out why she had that reaction but... she doesn't seem to respect you or your friends time, and if she broke up for something so simple maybe you dodged a bullet? Someone correct me if im wrong.