I'm either not being challenged or can't do it?!

Lately I've been riding horses as well as the ponies. My barn got a new instructor who's really nice but she isn't challenging me as much as my old instructor. With my old instructor I was just starting to do oxers on the ponies in some challenging 2ft-ish courses, which really improved my riding. This new instructor challenges me with things such as posting and some jumping without stirrups (A LOT!) but she only lets me do x rail courses... I know I can jump higher but I feel too awkward telling her. On the other hand, when I'm riding the horses I feel like my riding is terrible. She tells me I'm doing great and I don't know why I feel this way but sometimes I end up crying during my lesson. I don't understand why I always do this because she always says my riding is really good (and she's not the type of instructor who lies so your not upset) So anyways you're probably bored to tears my down but if you want to help me and my strange problems I would really appreciate it!!!

I'm not very experienced in riding, so forgive this, because it's not much related to riding, but: How old are you? You mentioned crying a lot for no reason and I'm wondering if that's bizarre hormones kicking in.