my daugther is 10 yrs old and wants a bigger bike should i get her a gas gas cadet or a rookie either way where is the best place to get a secondhand one from and what faults do they have

The Cadet/Rookie is tough to find second hand. There are a few but you could have to wait a while. The REV/EVO50 would be more plentiful and at 10 years old Your daughter should be able to ride one pretty well. I'd just have a look at what is available and then get the best of that bunch.

I agree with Telecat - the little GG's can be a tough find. You may want to have a look at an OSET 20.

Definitely get something with junior sized wheels (think they do junior & full sized wheels on the 50's). The seat hight is greatly lower, which is far better for someone of that age, as they can handle the bike better when putting feet down. I remember at around 11 years old (small for my age however) riding a friends full sized 50cc and compared to my small wheeled one it was impossible to ride, whenever I got stuck on an incline etc I'd struggle to hold the bike up.

I'd say just be wary of moving up to a bike that is too big for the rider too early, the 50cc's are normally powerful enough for the beginner and novice sections where we are, if the rider is adequete.

Young lad did the hard course today at BUMPY on a SW Evo and did really well. Once they get the hang of them the size allows them to work the bike as an adult would a bigger bike.