Would you date them or see if it would work out?

I've actually been in this situation myself. I went to school with this guy from the age of 4 and then we lost touch when we were about 14. But we got back in touch about a year and a half ago, once we were talking on our own away from friends and he told me he liked me and wondered if we could be more than friends. I think a lot of him but really couldn't be anything more because we had grown up together and when I look at him I can still see that little 4 year old boy looking back at me! I see him more like a brother or cousin and to me it just felt a bit incestuous(which I know sounds stupid, but it would just feel totally wrong) So I told him and asked if he could still see me as a 4 year old which he said yes but it didn't bother him as we were now adults. But I made it clear nothing would happen as wouldn't want to ruin the friendship anyway-which he accepted. His fine with it and hasn't effected us as friends. I wouldn't want to lose him as a friend as we have so many memories and experiences from when we were kids which there was noway I wanted to lose.
I personally would leave it as friendship and date other people, but everyone's situations are different and you haven't said whether she's giving you signs that she likes you-if she is then maybe tell her how you feel and approach the subject gently. But just remember if she doesn't feel the same way when you ask her things may be a little bit awkward for a while afterwards. But if the friendship is a strong one then I'm sure things will go back to how they were. :)

Well yeah that's the basis of a relationship is trust, and if you don't have that no relationship will work. There is a old saying a guy should marry his best friend because when you grow old together and you get ugly together it won't matter because they your best friend and yo love each other. If you keep the lines of communication open you should be fine, communicate properly and at times need when the heat gets turned up. I mean my ex is one of my good friends now, we just broke up because we wanted different things in life, I wanted success and to work so I can retire and she wanted someone to be there all the time. But we are like really good friends and still love each other but don't get back because there was too many conflicts. As long as you can communicate there should be no problems. Oh and don't lie or cheat. Cool?