Yeah, I would be very annoyed with that behavior as well. You don't need a controlling parent calling you multiple times per day until you pick up. Why do you think you keep picking up her calls? Do you feel guilty if you don't or obliged to answer? What would happen if you told her that you could only talk once a week/month/quarter and just held firm?

I have no idea how you handle the anger. I have similar issues with my mother. She would do the same sort of interrogating and then use the information to stalk me. I do not talk to her unless I have to and do not share any information about my life. She has trashed me to other people for this. I'm still very angry whenever I think about her or have to deal with her. I feel like my own social skills are extremely stunted in part due to her using me as a friend instead of letting me have my own friends.