I made a friend.. but..

I made a new friend at work! She’s pretty and she’s good to work with and we have the same birthday, we are very similar. We both have dogs. I was really excited to have her as a friend but then I noticed some weird things. Whenever we were in our friend group everything was about her. She would talk about the same situation for days. She also went though something traumatic, she was cheated on before and after having a miscarriage and essentially her “bf” told her that he was glad she miscarried (baby wasn’t planned). They then made up and actually agreed to try for a baby and she found him cheating the next day, like physically having sex with girls at their house. She told ALL of our coworkers about it. Everyone knew her business. Everyone came up to her asking about it and she would show them screenshots. And then she gets on Instagram and posts like 10 videos everyday about her messy life business. I thought this could be a long time friend but no. We tried several times as a group to make plans together and she says yes, she’s interested, she’s excited, etc. but she never follows through. It’s a bummer. I just don’t understand people that do this