Hi Sportyspice,
I'm 37 and have so far had one holiday with JY which I loved (NYC last September) and I am due to go on my second in October (Arizona Ranch), my only regret is that I didn't find JY sooner (I only discovered it via a work colleague last year). I loved my trip to NYC and made a good friend which I still keep in touch with, she is similar age to me and I think we had one person who was younger on our trip but as others have said don't worry about the ages just pick a holiday you want to do and go for it. I thought I would never get to NYC as I didn't have anybody to go with (friends either settled down and/or don't like flying so aren't interested in going to such places) I am so glad I did it and am planning my next visit.
It is nerve racking going alone but I met up with a fellow traveller the night before at a Heathrow hotel and we went to the airport together which I found really helped, unfortunately for my second trip my fellow travellers do not appear to be on the forum but do not let that put you off I'm still looking forward to my trip and counting down the days (was 7 weeks Sunday just gone). I am also looking at the Eastern USA tour for my next JY holiday as that looks so interesting.
So as everybody says take the plunge, you will be nervous but once you meet people at the airport all the nerves disappear and you'll enjoy yourself.
Donna