Mine used to be a 'clingon' but not so bad anymore but she still drives me nuts a lot. If it bothers you bad now, wait until you get married and have kids!! My first wife turned into Godzilla when our daughter was born. She became a bad helicopter mom and I needed supervision every minute that I was near my daughter and on and on. Postpartum depression? Probably but I had never even heard of that word back then but now it's all my fault and my daughter still doesn't speak to me 29 years later and my X says "I never said anything bad about you to her." Ok...sure.
All I can say is to take at least a psychology 101 course (a little more would be better) and save yourself some headaches down the road by learning who the crazies are and staying away from them or if you really love someone, learn how to bring out any problems y'all have and work on them. It's not 100% but at least it'll teach you how to identify who they might be and fix the problems. Also, it doesn't mean they won't turn into a crazy later but many that seem half way sane usually exhibit some traits early in life which will pop out later on.
Also, take a hard look at her parents. How do they act? Are they dysfunctional. If so, do they realize it and are trying to do something about it? It takes a lot of effort to break the 'chain'. Look up co dependency and control issues along with bipolar disorder too. I've dealt with all of that crap. It sucks for the people that suffer from it but it sucks even more when someone that doesn't suffer with it but has to deal with others that do suffer from it.
If I would have had a better education with this stuff, I would have been MUCH better off both psychologically AND financially! And keep in mind that the majority of the human race deals with one or more of the things I mentioned on one level or another. But if you rather not deal with the issues of others, at least maybe you'll learn how to identify them and stay clear. There are some that are easily identifiable but many more that are not.
Sorry for the novel....