Sadly I don’t think you can make other people do anything. If she was a kid you can teach her how to behave, but at 43 she is who she is.

You second question is why is she doing it to you only.. Do other people do it to you too or just her? I’d say if she is the only one who interrupts you, then it can’t be because your stories are too long. It’s likely because she doesn’t particularly care about your opinions and doesn’t think highly of you. She likely doesn’t respect you.

Generally speaking I am not sure why you two are friends as you both seem to have a lot of grievances against each other. Just not a good match in addition to her not respecting you. I’d maintain my distance and only interact with her if I must