I think she was expecting a relationship to be like a Disney fairy tale. Everybody happy all the time, bird singing while you do a musical number about your love for your significant other. She's stupid. This is reality. I actually got mad when you said that she mentioned that "you didn't have a squeaky clean past". She's acting as though you are married to women in other states, were a former criminal, or cheated in your past. Whatever, you're better off now. Every relationship she enters WILL fail until she realizes the difference between fantasy/ideal and reality.
...one can be sure of nothing until it has already happened...