An update on our progress this week:
Today I decided to take her on a little hack, like I had mentioned I was planning, to just try and refresh her mind and un-bore us both. I decided to go the "tricky way" which is past her field. We always have a hard time with her stopping at her friends and not wanting to move forward, so I wanted to see if we could work through it using your suggestions. As I anticipated, she got stuck when we passed her field. I tried the leg flapping once, and SHE UNSTUCK IMMEDIATELY! We haven't gone this direction on our hacks in a while because she is so difficult to move forward when we pass her field, but we did it and were on our way!
After our hack, I took her in the arena just to trot/canter around a couple laps to finish off our ride. There were two other horses in the arena, and I figured she would try to stop near them and refuse to move when I asked her for the trot. She tried it once, to which I responded by using the leg flapping again, and she unstuck immediately again! I didn't have to correct her anymore for the rest of the ride. We trotted and cantered a few laps, but I ended it fairly quickly as a reward to her for giving me what I asked for.
Between working with her using a combination of everyone's advice this week, to giving her a refreshing fun hack, I feel like we have made more progress this week than I ever anticipated. That isn't to say that she won't regress or that I won't have to use different tactics in the future, but I am really pleased with our progress!