Gorgeous horses You seem to have a really nice seat, great back, and an overall great apperance. I would like to see more rein contact, though. Maybe try to keep your elbows in a bit more, that may help with the contact/release. Your heel could come back a bit more, too, but I'm really strict on heel placement lol.
First pic: Horse's form leaves a lot to be desired. Very loose, almost hanging. Your form is quite nice; over the middle of the horse, eyes up, nice flat back. Quibbles: your reins are too long; I personally like to see a little float in the reins at release, but this is excessive. You could conceivably step down in your heel and push your lower leg forward; but since your base of support and back are so good, that is a quibble.
Second: You're too big for this horse/pony. He's got wonderful form over fences. Quibbles: In this one, your lower leg could be pushed forward to the girth. Also, you have a faux crest release; with your hands, esp. your outside one, floating above the neck. Seat, back and eye still excellent. Stepping down into your heel and pushing your leg forward, and pushing your knuckles into the actual crest would add lots of polish to this photo.
Third: Hard to critque eq from this angle. This horse is a nicer jumper than #1; but I suspect he's lighter in the body because it looks like your lower leg is flexed away from his side without the whole leg contact that is desirable. Your release here is the best of the lot. Can't judge much else because of the angle.