Ok biggest stand out to me about your riding is your hands and upper body. Not so much 'piano' hands, but that you are tending to carry your hands in towards your belly button, which in turn creates hunched shoulders, makes you lean forward, grip with your knees therefore putting the horse on the forehand.
To combat this, as I said in the last critique thread I commented on, it starts with lifting your chest. Imagine you have a pretty bow in the middle of your bra. Now focus on lifting that bow and inch higher. Lifting your chest, rather than jamming your shoulders back and down, will allow the shoulders to fall back into place without tension.
When you can comfortably ride with your chest lifted and shoulders relaxed, you need to concentrate on where your hands are. At the moment, you are putting yourself off balance and setting up for disaster if your horse starts playing up. Riding with your hands at your belly button with locked elbows is one of the easiest ways to be pulled off a horse if it suddenly kicks up its heels.
Push your hands out in front of you so that they're over her wither, thumbs as the highest part of your hand, and imagine that your elbows have weight tied to them that are always putting downward pressure on the elbow joints. Ideally you want your hands to be carrying very little weight, and your elbows to be the heaviest part of your arms. In this position, you will then have a much faster reaction time, and more space to move your hands should anything go wrong. If your mare decided to take off on you, and your hands were at your belly, where else can you move them? Where as if your hands are being carried with heavy elbows, over her wither, you can move them up, sideways etc.
You want to be riding from your legs towards her head, not pulling her head back to your legs ;)
I have a suspicion that your stirrups are too long as well (although I may be wrong, as it's very hard to see your legs in the photos). Take your feet out of the stirrups and let your legs hang down. The bottom of the stirrups should knock against your ankle 'nobble'/joint. Any longer than this and you will be unable to correctly apply your leg aids, and weight aids will be useless.
In the first photo I am guessing you're the rising phase of rising trot. I am also guessing that as you sat in the next stride, you thumped down quite solidly on her back and your lower legs swung backwards?
The BEST exercise to help you find your centre of balance, if to stand up in your stirrups. It's a killer, yes, but it works! Start at halt and have someone hold your mare for you. Stand up in your stirrups without hanging onto the front of your saddle. If feels easy, you're not standing up straight enough! You should be able to stand, with your weight in your heels, your back straight and shoulders aligned with your hips. Unless you can do this, you are not in correct balance, and will put putting the horse on the forehand and making them crooked.
Once you can do this exercise at halt, do it at walk. Walk and walk and walk until you can stand upright without falling down into the saddle or having to grab.
When you master it at work, try it at trot.
When you can do this easily, your centre of balance will be a million times better, and you'll find that your rising trot improves out of sight.
Thumping down on the horse's back is only going to give them a sore back, encourage them to hollow out, travel on the forehand etc.
I won't comment on your mare's way of going at this stage, as there is little point in giving you a list of exercises and things to work on, until your position has improved. You can ride transitions 'till the cows come home in the hope that she'll come off the forehand, but in reality it is impossible for her to work effectively when you're not yet in balance and allowing her to move forward freely. It will come, don't panic!