R.I.P. Grammy...We love you!

I haven't posted in a couple of days... On Tuesday, I got off work and got out to the barn around 2:30. Grammy, our resident senior citizen, was laying down. I thought she was just being an old retired fart sunning herself, and she got up when I drove by and meandered off in the pasture.
Nobody was at the barn yet, and the new girl Alissa was supposed to come out, so I decided to sit down and wait for her so we could ride together.
I sat down with my tea in the chair at the front of the barn. I could see the part of the pasture Grammy and a couple of others were in. She grazed a few minutes and then she just came to stand by the fence, not grazing, just standing.
After a few minutes, she started to spin. Sometimes on the forehand, sometimes she was actually executing a decent walk pirouette. I though, well, the poor old girl is just stiff and having a hard time laying back down. After 2 or 3 minutes of this, it was getting more frantic and I texted Casey to see if she wanted me to bring her inside. No sooner had I finished sending my text, Grammy goes FLYING sideways. A very unbalanced sidepass. She spun a couple of times here and there, bumped into the fence trying to get through the gate that leads into the dry lot connected to the grass.
I jumped up and ran out to get her. When I got to the gate, she was spinning towards the end of the lot still, but she saw me and sidepassed over frantically. I grabbed a halter and ran in, but I quickly became aware that she had lost control of her legs and after she nearly knocked me down, I had to get out before she knocked me down. Her erratic movement had spooked the three ponies that were turned out with her, and they actually began attacking her.
I'm not sure if they were really trying to hurt her, more than likely they thought she was trying to theaten them, but eventually one knocked her down. I ran in and chased them off, and walked over to her. She got up as soon as I approached. She stood still, so I put the halter on and lead her out...she seemed to have regained control.
I was able to get her out of the gate, and when we were almost to the doorway in the middle of the barn, she started to lose control again. She bumped and stumbled through the narrow passage and I somehow was able to get her in a stall. Not the most ideal place, but there was no way I could get her to the roundpen - she would have crashed all through the barn aisle and could have potentially fell on me. She was extremely hot and breathing heavy, so I grabbed the hose and started hosing her. She was able to stand still a minute or two, then she'd spin again. I eventually just stood at the door hosing her to avoid a potential squishing.
At this point, every single horse in the barn was turned just staring in our direction. The horses outside were FREAKING. Eventually she collapsed, and I let her lie. She tried to get up every time I got near her, and it was better for her to be still and not thrash around in the stall. In a few minutes, which seemed like hours, the vet and a couple of boarders arrived. By this time her breathing had returned to normal. Dr. Smith was able to get her up and we got her into the roundpen outside. She ate a little soaked grain and drank some water. Dr. Smith advised that we hose her again in about 30 minutes, keep her in the roundpen, and call her if anything changed.
She was filthy from laying in the soaking wet stall I hosed her in, so we gave her a little bath. She was seemingly fine.
I put her back in the roundpen and it was then I noticed her skin wasn't looking quite right on her neck. I did a pinch test and she was VERY dehydrated. We encouraged her to drink more, but she wasn't really interested. She munched on hay for a couple of hours and seemed to be doing fine, moving normal again.
Then, about 5, she started to spin again. She eventually went down again for a few minutes. Then got up, ate and drank again, and had another spell very close to the last. When she fell that time, she really fell hard.
We decided to let her be in the roundpen for the night, because euthanizing her that night would mean she would potentially have to sit for some time until someone could come dig a hole, or remove her body.
She survived the night, apparently well, because the next morning she was nickering her very distinctive neighs for her breakfast at the gate. As the heat got greater, she started to have spinning and falls again I was told. They euthanized her early that afternoon, and she was buried a couple of hours later. We planted some little pink flowers on her grave today.
We're all still pretty sad about her death. She did live a long life - she was 30. She didn't always have an easy life, and she was starved before she came to our barn. That's somewhat comforting. Her retirement with us was a good one. She was actually healthy and sound enough to be ridden a couple of years ago.
We will miss the Gram! :( I had a picture I was going to post, but this computer refuses to let me for whatever reason.
I let Melissa ride Amber yesterday, and Amber was okay. She did a lot of bracing, speeding around and running through her. She cantered off a couple of times. She wasn't being bad persay, just trotting around like "I DEFY THEE, STRANGE RIDER!"
It was similar to what she did with Victoria, and everyone else who has tried to ride her. I got on a few minutes and worked her very collected and on the bit for the first time in a long time. Today, I was working her on a loose rein as usual, but she decided she wanted to speed around and ignore my seat, so I collected her a few minutes, and then when she decided to half-heartedly listen to that, I did transitions and made her back when she did those rather unresponsively. A few times of that, and she gave me some really nice trotting.
Waiting for the vet to give us a call and let us know when the chiro can do her at the clinic. Can't wait...it's disgustingly boring and Amber is literally dragging me at jumps, even ground poles. She's displeased and bored with her walk-trot lifestyle.