To add to MBP's great critique, I also see that you are ready to start influencing this Mare's way of going more.
she rarely bends to the inside, but when she does, one can see her offer to reach more forward and down. When you feel those "offereings" I would take the opportunity to move her into long and low for a few strides if she will keep it. She still has a lot of underneck muscle which indicates that she may look soft, but is still bracing internally against the rein. She also seems to hold back, kind of "mincing along" in her trot. If you can get her to reach down and forward , a lot, she probably will slow the rythm of the trot but extend the reach of reach stride. You can encourage this by putting some leg on to galvanize some energy, but keeping your posting speed unchanged, so if she zooms forward, she will come out of sync with your posting speed, and will naturally slow to match you.
Long and low, bend to the inside and more engagement in the trot, but not FASTER.
I commented on your videos a ways back and still say that you have a lot of potential to be a very nice rider!