The thing is neither of you gave her a criteque at all but just negatively commented on the fact she is jumping (Which she is probably extremely proud of and now feeling a bit crushed)
I tend not to critique much, as I personally don't feel I have the knowledge to accurately critique someone just from pictures. If I am going to comment on someone riding, I prefer to see them in person, and know a bit about them and the horse.
I wasn't trying to be rude, I was just incredulous, as i've never heard of anyone jumping before establishing a canter while under the direction of a trainer/instructor. The only people who I know that have done this have either ended up hurt, or become the type of rider who tries things before they or the horse are ready.
I'm sorry if I offended, but I really think that it is just asking for trouble. If you can't maintain a solid and secure seat in a canter, what hope do you have if the horse decides to stop, or catches a leg on a pole and stumbles, or any number of other things that may go wrong when jumping?
Just my opinion, that's all.