Tell me about it!
I shared an office with a co worker and it was like working alongside a tannoy. Except that you can turn a tannoy off! You could not turn "Tina" off. She would ramble on and on and on about aspects of her personal like, holidays, her pets, laser eye surgery, etc. She was very attention seeking.
I would tell her that I had to get on and start typing. Then it would be "Member, MEMBER are you listening?"
Id tried techniques like "Id love to see your holiday photos over coffee Tina but I NEED to get on now". She would be quiet for a few minutes then begin on another diatribe.
It got so bad that I had to periodically go out to the toilet for a few minutes. Or go and sit in the student drop in center to finish a task (we worked in a uni). Eventually I had to speak to the line manager as it was affecting my ability to do the job and the fact that I could not concentrate was stressing me out. I emphasized the fact that "Tina" seemed a very pleasant person but she was just too chatty, and did not appear to be able to recognize social cues that others were working and trying to concentrate. The manager kicked it into the long grass and nothing was done. She could so easily have solved it by having a chat with her. Eventually I had to go to the HOD and make a formal request to work in another office away from "Tina".
I would first make sure not to respond to out of the office messages and simply repeat in a terse "busy busy" manner that you dont take calls from co-workers outside the office. Try to use a brisk professional manner in the office which does not encourage intimacy, and end the conversation by walking away or turning back to your work.
If she continues to disrespect your boundaries then you need to speak to your line manager. Keep it simple, non emotional, and professional. This is affecting your ability to do your job efficiently as well as dynamics within the team.
Lets hope that yours is a better manager than mine.