I used to be the same way with my boyfriend (of five years and we've lived together for most of it) Before I was diagnosed with OCD I also had a very short temper with him and would clean and straighten all the time. I would also get very irritated if he didn't put his things away etc. Since I've been on my meds. he claims I am a completely different person.
Now, my suggestion to you....when I first discovered I had OCD, it was many things that added up! I went on-line to yahoo health and started reading about depression etc. because I was so depressed for such a long time. Then on the depression page, I came across OCD and when I read about it I was in shock because that was me! If you are able to get her to maybe read about and see how/if she relates, then maybe she should take the first step by seeing a therapist.
On the other hand, I am a actually a manager for a maid service and I FIRST HAND know how some people are just "clean freaks!" If she is one of them, then be grateful that she'll keep your house clean
. Good Luck and Congrats on your wedding!!!!!!