This is certainly a dilemma and I hope with time God illuminates your path.
If you were my little brother, I would advise you to consider to look for traits such as kindness and compassion and to avoid someone who is prone to gossip or feels she has to compete with others (you know, have a fancy car, bigger house,, flashier diamond). You might want to consider how each woman handles adversity, does she handle it calmly or with courage, or does she look for others to bail her out? Your children will be learning coping skills from both of you so you might want to take a step back and consider which one you would like best as a role model for your children. I wouldn't rule out one if you meet her family and find out they are crazy or something, but instead look at how she treats them and deals with any conflict. Is she a pushover and can't stand her ground, is there tension, etc. Have you had any disagreements with either of one? If so, how was the conflict, even a small one, resolved? How does each one handle her finances? Many stressors come in a marriage around finances and debt so this is a big area to look at.
The advise to pray is probably the best. I've known happily married couples who did everything wrong, they got married too young, or too fast, etc and it worked out brilliantly. Others over-analyzed (probably the list I just gave you) and it didn't work out so good. Perhaps the key is to really know who you are loving and make sure you are not loving an ideal you pictured in your mind. The key is to find someone you can walk through life with and build up each other along the way.