I think it would be in your - and your horse's - best interest to hold off on jumping for a few weeks while you really solidify your basics. In all of these pictures, you've lost your leg, thus propelling your upper body forward, and your clutching at her mouth for balance. See her pinned ears in some of the pictures? She's uncomfortable - and you want to fix yourself before she decides it's easier to start refusing.
You really need to work on your leg. At the moment you're standing on your toe and launching off of it - you need to educate it to stay at the girth, with the weight in the heel and an even contact throughout. Work on two point - lots and lots of two point. Work without stirrups, too. Try tying your stirrup leathers to the girth at first so you can feel exactly what your leg should be doing. Do trot-poles, cavalletti, etc in your two point. Focus on not moving AT ALL except for a BIG release with your hands only - not your body!
When your leg is suitably educated to begin jumping again, do what you were doing with the trot poles, but make them into small jumps instead. Come into them in two point, push your weight down into your heels, and a stride or two out, release. Hold that release through the line - let your mare figure it out. They usually do that better than we do!
I like your focus in these pictures - you're looking ahead, rather than down, which is very good. Don't change that! ;)
I think your mare has the potential to be quite a cute little jumper, but right now she also needs more education on the flat. I think a lot of people forget just how important dressage is to the overall equation. Right now (judging by the flat pictures) you're riding her downhill, with little to no leg aids, and using your inside rein to turn her. I'm going to copy and paste what I wrote to someone else about the dressage basics - read it, learn it, do it! It'll make such a monumental difference in your riding.
A lot of aspiring dressage riders focus entirely on that lovely, round outline we see Moorlands Totilas et al. Trotting about in, but the part you need to be training is the rear-end. Roundness will come in time, and isn't necessary at the beginning levels anyway. The first thing to work on is forwardness - you want him happily moving off your leg at all three gaits, and slowing and halting off of your leg and seat. Experiment a little - you'll notice that when you get up in jumping position, he'll speed up, and when you sit back down he'll slow down. This is good, as it teaches you a powerful lesson about what you can do with your body, and it's the basis for everything to come. Work on adjusting your posting to what you want from him - in the beginning you'll want to post lightly (no butt-smacking) to encourage that big, forward stride. Later on, you can sit longer than you rise to help him shorten his stride, and when his back is educated and your seat is too, you can sit and make micro-adjustments via the motion of your hips.
He looks a little resistant to the bit and is turning to the outside. Have his teeth been checked lately? Make sure that's all in order, and then you can work on the education of his mouth (after you've got him forward-going and relaxed!). Your outside rein should be stable and steady - an ever familiar thing for him to rely on. Your inside rein can mimic that to an extent, but with 'gives' - second-long softenings of the rein to encourage and reward yielding, flexing, etc. At this point you can teach a basic half-halt - using the educated seat you will have attained, sit deeply for a stride as you would if you were asking for a down transition, squeeze slightly with your leg, and slightly pressurize the reins (no pulling!) - then GIVE. If you don't get any response, give anyway. The half-halt request should only last a stride - if you don't succeed, give and ask again. Make that your cardinal rule for everything!!
Once you've both learnt balance, go, stop, turn, all that fancy stuff, you need to address straightness. OK, well, ideally you should address this right after "go." Work on easy leg-yields, shoulder-ins, haunches-in, etc. With a green horse, it is preferable to get one good step of a movement than twenty iffy steps. Instead of turning down centre line and leg-yielding to the wall, turn down quarter line and ask for a step or two, straighten and go forward, ask for a step or two, etc. Same with shoulder-in, except on the wall of course. Start by riding an accurate ten-metre circle in the corner to get your horse in the correct position, and then proceed.
I also think that working with an instructor will help immensely. Learning dressage is kind of like memorizing an encyclopedia - you don't want to just dive in a do it all in one go. Having someone there to present everything to you in managable chunks is so much better than learning it all at home and then trying to remember while you ride! :)
Rather than equitation (although it is important), we need to analyze our riding pictures for function. Although your basic eq is pretty good, you need to be more of a 'rider' and less of a 'passenger.' Now, this is all just from one picture, but in this shot you're very much riding 'front-to-back,' when the opposite is what you want. What I'm infering from this picture is that you want your horse in a 'frame' (hate that word.), but you haven't taken the necessary steps to get that nice, round outline we english riders like so much. If you take a look at the training scale:
You will see that collection - or, the time when roundness and on-the-bit comes into play, is the very last factor. Everything else needs to be in place first. What I'm seeing is a lack of hind end engagement, because the rhythm and impulsion was sacrificed in exchange for a pretty headset. There is also limited relaxation, because of your tight hold on his mouth. Roundness needs to come from the hind end - and consequently, from your legs. It would do you and him well to do a lot of loose-rein work, to give you the feel of adjustability exclusively through your seat and leg, and him the chance to really use his hind end and start working over his back on his own. He'll figure out the balance better without help. Right now it seems like the reins are your lifeline - it doesn't look like you would be confident to get rid of them and ride without his mouth. That's not the case - once you do a ton of on-the-buckle work, you'll both be much more responsive to one another.
Basically, once you've got the hind end, you can start to work on riding into a soft half-halt up front. Between half-halts there needs to be a 'give' - basically a steady outside rein and elastic inside rein to encourage him to accept the bit. It may take a while - he may be evasive at first because I think he's used to an overly tight rein and a twist-and-pull flexion to get his head down. But putting the time in will definitely be worth it.
Sorry for the novel - I always get carried away with critiques ;) But it's important for us to ride our horses correctly and sympathetically!
Anyway, there is absolutely nothing stopping you and your mare from doing very well - just put in the time and effort to do the "tedious" training stuff, and you will both benefit from it so, so much! Good luck!