I think it’s not weird to feel hurt if your best friend sleeps in your exes bed, especially if she was on the couch at his house at the same time. It would be so easy to have slept on another couch like he did, he at least was respectful and stayed out of the room. I don’t think you acted in way to intentionally hurt her, but you did and she is letting you know she is struggling with it and needs some time. She’s being very mature to work through her feelings first and I’m sure she will be willing to hear you out in some time. You’ve apologized and reached out to check in on her, so I think she needs to be ready to hear you out in order to move on from things. Let her come to you when she’s ready and offer support from the sideline until she is.