I love my mare. She is very expressive and lets me know what she is thinking/feeling at all times. Of course she is also an Arab so that plays a role too. I don't think you should rule in or out a horse just based on gender.
I have found, in my experiences, that the mares I have ridden took longer to bond with and decided who they did or did not like. There seems to be more of a wall you have to break down with them. Once you do, you will have a best friend. Also, the mares have always seemed to try harder, be more fiesty and show more heart. The flip side is that they have also shown more attitude and resistance when they didn't understand or just didn't want to do something. I found this regardless of them cycling. My mare tends to be an angel when she cycles - more so than when she isn't.
The geldings have been more predictable from day to day. You know what horse you have waiting for you at the barn, but to me they have always lacked that spark and fire. This is not ture for every gelding, just my opnion. They also seem to be more friendly for more people so have worked better for that horse when your mom comes over and wants to ride or your friend from work. They seem to trust better at first adn take things in stride. Also, they seem more forgiving and don't seem to hold a grudge.
I would just go and check her out and see what you think of her. If you are having a hard time ask yourself that if you didn't know the gender, what would you think? Good luck!