Assuming she has good hygiene, - which usually isn't a problem. I find the most unattractive thing about beautiful women is sometimes they suffer from CDD - 'chronic dissatisfaction disorder"
They may be a wonderful person, but there is a pervasive negative outlook on people, life, food, job, relationships. They tend to whine a lot, and the closer a person gets to them in the relationship, the more comfortable the women becomes complaining about things. This may not be your problem, but try focusing on the good, not the bad. The world can be a pretty shit-ridden place, but its a wonderful place too. You choose.