You needn't worry Wendy, Virgins in flight entertainment is pretty good even on the older planes in it's fleet, on the newer ones, it's even better !.
The actual system you get does depend on which plane is being used on your route - the newer the plane the better the entertainment system. All planes have seat back tv monitors for every individual passenger.
I'm not absolutely sure, but I believe the most basic system, used on the standard 747, has at least 6 film channels, 2 to 4 Tv channes, and various radio and audio channels also. On 747-200's, you get more channels plus the option of Nintendo video games controoled by a pop out controller stored in the seat arm that also works the TV channels. I haven't travelled on a 747-400, but I believe they have up to as many as 18 film channels, more tv and games, and a few other niceties. I don't know what system is used on Airbus planes.
Kids get a backpack on entering the plane that has various stuff in it to keep them entertained, and there is always some programming aimed at kids.
Checkout the link below for more info on In-flight programming direct from Virgin:
Vurgin Atlantic In-flight Entertainment Info
This link gives you some info on their facilities and provisions for kids :
Virgin Kids
I hope this helps !
