I think that it is fine to date someone quite a bit older or younger if you find yourself compatible, enjoying each other's company, and attracted to one another. Just prepare yourself, there is something shocking and kinda weird in realizing that MANY of your memories and reality happened before your date was even born. LOL. BUT, if she seems interested, what do you have to lose? Certainly these days age shouldn't be a consideration, at least not one that is high on the list. And, on the plus side, if you DO spend time with someone substantially younger than yourself, you will find yourself feeling and acting even younger yourself. Pace yourself!
I was told once that the rule of thumb for guys is half your age plus seven. So, that would mean 50/2+7=32 yrs old. I'm not too sure what to make of that rule though because if the guy's 100, by this same rule it's alright for him to be with a 57 yr old.
I think it completely depends on the people, but I'm not too comfortable with the idea of large age differences myself.