Can any (breed, age) of horse jump?

Any breed of horse can jump. Of course horses with longer legs are more apt to be introduced to the jumping field because they get over higher jumps faster and easier. I wouldn't recommend jumping a small horse if you are a large person, though they could do it. Not all ages can jump because of bad joints and frail bones but even old horses can jump if they are in good health. I have a 16 year old TB mare and I jump her. Your horse sounds like it would be just fine jumping

if she is sound yes,there are breeds that are just not meant to jump (Clydesdale) but your horse as long as you dont push it too much in the beginning should be able to,you may want to have a vet check that she is safely able to as far as her bones and ligaments go thought.

yes it should be fine. if it was me id loose jump her fist and start of small xXx by the way this hole a horse has to be 5 to jump is bull poppy. ive seene foals willingly (no one near it) jump over different things because it wanted to. you shouldent jump a young horse to much incase it goes souer thats all. and yess all horses can jump some better than others thow

i always been a fan of a vet check before starting a horse to jump. you always want to be sure that the horse has finished growing, and each horse will finish at their won pace. also, when you do decide to start jumping, you may want to add a joint supplement just for a bit extra support.

Depends on her condition. If its good, then yes. It also depends on her temperment and willingness to jump.

5 is old enough, just barely. Most horses can jump somewhat, regardless of breed, but the question is how well. I'd free-jump her fist- if she's a good natural jumper, fine, but if she's really bad at it or a dangerous jumper (Very loose/uneven, poor bascule, jumps like a deer, ect.) don't even bother jumping her under saddle.