Make it bigger. I think it's a common mistake people make when teaching horses to jump that they don't want to give it something TOO big (which is sensible, obviously!) but they go too much the wrong way and don't give it anything to jump at all! Some horses are quick to work out how to snap their feet up and use their back even over a tiny jump, but most are not, and won't learn to jump properly over something that doesn't REQUIRE them to jump properly.
True I have not tried that yet. How high should I put the jump though? and should I canter her into the jump or trot? I guess i'm not sure when I should start her cantering into jumps, at what point is she ready?
Loose-jumping is a good idea as she can discover her technique for herself, in her own time and using her own balance, without the interference or influence of a rider. I would pop her over a crosspole in trot just a couple of times, and then get her to do it from canter. When she can canter over it without tripping or knocking the jump, I'd put it up to 50/60cm upright and get her to come in at canter straight off. You really don't need to be too cautious, they work it out pretty quickly!
As for the last question, personally I'd say that if you can control her direction and speed at canter riding her on the flat, she's ready to jump from canter with you on board. Make sure you keep your leg on and ride her forwards, do not just sit there - creating impulsion is YOUR job, and she will not jump properly if you just amble in half-heartedly - but keep a soft elastic contact and don't try to "hold" her or get her to take off in a certain spot, she must be allowed to work it out for herself without mum's interference. When people are teaching horses to jump they often try to control too much!... You take care of forward and straight, but the rest is up to her.
Remember to have a clear groundline for EVERY jump, whether loose or ridden, even just for a crosspole. If you're not telling them where to take off (which you shouldnt be at this point) you need to help them judge it themselves. A placing pole 1 stride out always helps too.
or if you canter already (assuming its a young horse) just ask for the canter transition on the take off stride to get him to pick up.
