As a bit of advise from someone that has dated a few clinically crazy girls (I was unfortunate and fortunate enough to be attracted to the crazies, not that this advise would work if you have a chemically imbalanced girlfriend, but rather if she just seems like a normal emotional girl). One should always try to understand first and then explain, rather than the other way around. We tend to want to say our side of the story first and have someone understand us first. This often creates a situation of two people talking over each other and each party already formulating an answer/counter argument in their head, to the argument the other person is bringing, before they even finished their point.By doing this you listen better and can resolve an issue much faster without getting side tracked with a million other arguments about things that aren’t really relevant to the current argument. If you can’t communicate in this way, or at least be cognisant of trying to communicate in this way, the relationship will never work.
In the end it does create tense family get together’s, and it’s never ideal to have issues with your significant other’s family or friends, but if you really want to be together and if you have made a list of what you like and its really what both of you want, then the relationship can be salvaged through transparent conversation.