How high can my horse jump?

My mare is a 14.3 hand welsh/QH. She is 7 years old and has been jumping for the last 3 years. Usually we do jumping in the spring, summer, and fall, then I stop during the winter as it is cold, the ground is hard, and there is a potential for ice. I have just started her on jumping again for his year. I started her 2 weeks ago first on cross rails, then low verticals, then a small course, then higher verticals. She HAS been in training this whole winter though, so I didn't just begin jumping her when she wasn't in shape. I always do hill work, and walk, trot, and canter circles in the winter to keep her fit year round. My main questions is, how high can this mare jump? I wish I could say that I'm a great horse person and I know my horse well enough to tell her limit, but the problem is she loves jumping so much and tries so hard for me that I'm afraid she'll hurt herself trying too hard. Yesterday we did some work over 2'6" verticals and she did great. It when I raised it to 3' she hit it. Thinking maybe she hadn't expected the raised jump I tried it 2 more times and she knocked it both times. So I decided to stop before she possibly got hurt and thought maybe we would work on it again in another week when she gets more muscle. I have no idea what the horse to jump height ratio is, or if there is one. I would love to jump a 3' course this year with my horse for the 4H show, but I don't want her to hurt her legs or overheat. Just if anyone.could tell if here is a decimate limit or whether she should be able to jump that high that would be great. We jumped one 3'3" jump last year but that was when she was in top condition and it was only a single jump, not a course like I'd like to do.

She probably needs to build more muscle to clear higher jumps. My horse was clearing 3'6" jumps at one point long ago. I consistently jump 2' 9" now and she could probably go higher as she has built a lot more muscle and is engaging her hind end more than she used to. I think you just need to condition her more to help her have the muscle and fitness to clear 3 feet or higher.

She may be able to do the 3 foot. I have a friend that has a horse about your size and she can school a 3'6" course. I would say get her in better shape. I really don't think you will hurt her tho, I've seen pony jumpers clear 4ish. Good luck!

There's a big difference between hitting a jump and struggling to get over it. You might have just put it up to high at the end of the work out. My pony will clunk around 2'9" fences when when she gets tired but she jumps solidly at 3'3". Try not pushing her so fast. Work more on the quality of the jump rather than the height. She needs to build up those strong hind end and back muscles.

I'd say sticking to working on her flat work and lifting her back and coming from behind three times a week (dressage), conditioning once a week (hill work), low jumps once a week, and higher jumps 2'6"-2'9" once a week; would be a good routine to get into and then when she's jumping around at 2'9" like it's easy peasy, start adding in 3' jumps one at a time. You have to work up to them, you can't just run 10 miles your first time out, have to practice and work up to it :)

There really is no height to jump ratio. Stroller won the Olympic silver in 1968 and he was only 14.1hh (aprox).

Depends, I had a 13.3h that was part cricket. Jumped 126cm on that sweet pony.