while i don't think there's anything wrong with a female being a certain age and still a virgin, there is definitely an age range where upon learning of someone's still-intact virginity, you do raise an eyebrow. for me it would probably start at around 20. if i met a 20 year old female and found out she was still a virgin, my reaction would most likely be, "wow, really?" most girls in this day and age have lost it by the time they are 16. the girls i have dated lost it anywhere from 14-17.
as far as waiting goes, i'm in my late 20s right now so i think the likelihood of dating someone who wants to wait 6 months to have sex is not all that likely. in the past few years, i think the longest i had waited was about a month...maybe a little bit longer. i had no problem at all with that. the girl was a nice catch, and i was glad she wasn't the type that hops in bed with me on the first or second date. sometimes it can be cool to wait a little while and build up some sexual tension. other times it's cool to get right down to it and commence fucking each other senseless with no delay.