Before intelligence, the number one risk predictor is family. Do their core values align with your own? Politically, are they pro freedom and anti government interference, or are they spiritually lib? One may surreptitiously infer the answer to these questions by determining how they feel about more innocuous subjects. For instance, how a family feels about property taxes tells you how they feel about public education, taxation, government spending. Not treating incentives as natural law is an implicit declaration that one does not understand the world from first principles.
Should you encounter a prospective partner with a terribly misaligned family (mine was misaligned at every level) there is a high likelihood their children, thus your significant other, will default to that belief system if ever under duress. It is what is most familiar to them. There is also a case for genetic influence which we won't cover here.
However it's not all doom and gloom. Intelligence matters; however, only if above a certain threshold. Intelligence, being notoriously difficult to quantify, makes this metric unreliable. Personally I'd only resort to it if she is abnormally intelligent in a very self evident manner, and confident enough to believe she is better than her parents. Even then, this only applies if your significant other's core values align with your own—remember, we are primarily concerned with instinctual behavior, that which surfaces under stress!
If at some point I happen to be with a woman that goes against the wisdom of this entry, know that I capitulated out of fear. At this point in our societal cycle, good women are rare. But you have time and a clean slate. You don't have to capitulate.