Fiancee Problems

My finacee's very active, so she's often out drinking with her friends (I know 90% of the people she meets, since we're in the same community)
What bothers me is not that she would cheat because if she did, someone would tell me right away and I would have a legitimate, black and white reason to end our relationship.

What I'm concerned about is that she would get too drunk, making her an easy target for sexual harassment and/or assault. This never really bothered me, until a few weeks ago when some big shit happened. That left me a bit uncomfortable about her going out to drink, but she made it worse by going out to drink again not once, but three times after that incident had occurred. The past few weeks was a very important period in my life, and my productivity dropped significantly. I decided that I should not have to spend my time worrying about her when I had other things to be concerned about, so I suggested that we break up. She talked me out of it, and I agreed to let it go because she's always among people whom I know and trust.


But last night, a man followed her home, which is when even the people I trust are not there with her. Thankfully, a police officer was around and the situation didn't worsen.

I'm obviously not going to ask her to stop drinking, since that's basically telling her to stop meeting her friends. But I feel that I should not have to be worried about her every time she goes out.

What would you guys suggest, do you think that I should just call off the marriage? We've been together for 3 years now, and this drinking problem has never really been a "problem", until recently.

Or maybe I am just being paranoid?