I've skimmed through most of the posts.
My thinking is: If she has a problem at the lope, then lope, lope, lope, and lope some more! If she doessn't have muscles developed yet for a slow lope, it may be uncomfortable for her. Or she may not understand. Or...... this may be how she is.
I had a horse named Scooter for one year, while my horse Beau healed from a big injury. Scooter was fantastic. He was so soft in the bridle and SO sensitive to any of your cues. He was constantly listening to what you wanted him to do next. Scooter only had 2 flaws 1) He was hard to catch. He didn't run away from you, but would just keep walking slightly away from you. 2) He did not know how to lope "normal". I rode him all summer long 4+ miles every single day, and every time I'd want him to lope resonably slow and relaxed, my butt was bouncing out of the seat, because he mostly just hopped. Running? Oh, he'd flatten out like a racehorse. But he would never figure out how to lope. Just never could.
So..... I know it's possible for it to just simply be the horse. Which potentially may be the case here.
With Squiggy, I'd just spend lots of time loping. Develop those muscles. Do lots of circles, and lots of serpentines, and lots of simply slow loping for a mile or more (when you get her in good enough shape). Eventually, you will relax. She will relax, and she should smooth out.
I am 100% for breezing a horse. I feel like it gets the silly out and gets them more focused. Wouldn't hurt to try it. Just make sure you do so in the safe open area, where you could one-rein her down to a stop if the emergency arises.
Red, it does him good to breeze. He would run himself dead though, if I let him. So he is a bit hot after I breeze him, but I can make him do a nice lope afterward. I've taught him that I'm in control of the speed. He basically western pleasure lope real nice, although he can do better on softness in the bridle (hence why he's going to a reining trainer in a few days, so I can learn better how to ask him too).
∞•*˚ Βгįťţαňγ ˚*•∞
It is not enough to know how to ride; one must know how to fall.