Julie,
I just saw your original message to the Editor. This will be your first holiday alone.
Believe me you will be absolutely fine. I believe there is quite a big group going. I have been on several singles holidays. There is always a very varied bunch of ages and personalities. I have just booked today. I think I am a fairly normal person. Im 45.
I came back from Tunisia last week booked with another singles holiday company. Originally there was supposed to be only 4 of us going. A bit daunting. Only 2 of us were on the same flight. We didn't even know who was who (at least with JustYou we will all meet at the airport). In Tunisia, the other girl who came from LGW - it was her first time on a singles holiday. Luckily, she was of a similar age to me and we got on and wanted to do the same thing - sun, eat drink, dance!! The third person - a 60ish old man had already been there 4 weeks (made no friends - in fact made enemies) and the 4th person was another young girl who arrived the next evening and wished to spend her holiday alone.
But I am pretty sure that the rep over there with us will be very attentive. Everyone, whatever age, personality, will have a brilliant time.