Girl obsessed with my fiance, how do I handle this is in a mature way?

My boyfriend and I just got engaged about 2 weeks ago. We have been together for a year and a half. This girl he was friends with and knew in high school has literally been in love with him since his sopre or junior year of high school. He got a job and it turns out that girl works there too. She is always touching him, trying to hug him, she made him a cookie, she's always waving at him when he is working, and she makes strange comments towards him. He tells me everything she does and I appreciate his honesty. I really need to know what to do and how to handle this maturely. He has told her not to touch him and she doesn't seem to get the hint. She knows we are engaged and still wont quit. He gave me her number and I was going to put it nicely but tell her to stop touching my fiance inappropriately but I thought that may start a dumb girl fight so I didn't. Any suggestions on what I should do and how to handle this the right way? Thanks! Mature responses please :)