Hitting the keyboard a little too hard BOTR?
Actually I had a similar situation, it wasn't stalking per se, but just a very one sided friendship. I met this woman, I was new to the area, she was nice. It started to get a little crazy, she wanted to come over all the time, calling a lot. For my Birthday she went crazy, like a cake, two cards (one musical), two bottles of wine, balloons, a sign, and a blouse. It was embarrassing and weird, I couldn't figure out why why she liked me so much. I am a nice person, but I have never had this before. She would call like five times in a day. I really thought about whether I wanted this friendship at all, I am kind of an introvert, I like my alone time. So I decided I wanted the friendship, but I started setting limits and was honest about my needs. She totally was fine, she respects my boundaries. Had she not, I would have ended it.
So your friend just has to set boundaries. If she cannot do that, then she has the problems. If the woman does not respect the boundaries, then it is time to end the friendship, if she doesn't respect that, it's restraining order time.