What would be the best breed for a 12 year old girl? She is about as experienced a rider as a 12 year old can be? Also, are there any breeds that take more upkeep than others? Should I be worried that I'm going to get her a breed thats going to take more time than we have to give. Not that we don't have a lot of time to give, but are there any that are practically full-time jobs that I should stay away from? Thanks.