I work at a fairly large company, and I’ve been in several different departments and I’ve worked with multiple different personalities some I liked, some I didn’t, and some just drove me up a wall. You can’t control her like many of the others have said, but you can start to distance yourself and I think she’ll eventually take the cue. if she doesn’t take the cue, you can request, maybe some form of mediation with HR and her or you could disclose it to whoever you report to. I’m not trying to get her in trouble, but maybe there’s a way that they could help you not to have to interact with her as much making your work life more pleasant. Again, trying to distance yourself is the first step but you have options if you need to escalate it for your own mental health and for your work performance because I’m sure her bringing you down isn’t helping you at work believe me I’ve been there. I had an atrocious boss who ended up getting fired, because so many of us went to HR. And my work performance it was so much better because I enjoyed being there, and I wasn’t scared to ask questions and I was more vocal and just in a better mood.