So pretty much what happened was...
She was always pretty healthy but she was much smaller than a normal 2-year-old beardie should be. I fed her a bunch of dubias (the colony you sent. Thanks again) and she threw them all up the next day (she ate A LOT (like at least 30-40 large)) and sat under her light for the rest of the day. I left her alone thinking she just felt a little sick from throwing up so much. The next day I took her out at night and she was almost completely limp and could barely keep her eyes open for me. I figured she could be dehydrated (again because of the vomiting) so I gave her as much water as she was willing to drink and she seemed to perk up just a little. After that she went back to being very lethargic again so I decided to take her to an emergency vet (it was already at least 11pm by now.) After a 45-minute drive to the vet and at least 2 hours of total waiting time the vet finally came in to see her and Sandy had perked up a little again (granted, it was way past her bedtime so part of her lethargy was from being sleepy) and the vet gave us some Lactulose to try to push anything else through her system. She got on me a little bit about Sandy's size and not having a thermometer in her tank (go ahead, let me hear it. I should have a thermometer, I know, I know) but complimented me for doing everything else right. During the exam she said that it felt like Sandy might've started to form some eggs so that had me a little excited. We took her home and she stayed under her light again the next day so I took her out and it was the same thing all over again. I figured I'd give her another soak and try to get some food in her. I took her to the bathroom, set her on the counter, and started to fill then sink. It was then that I looked over and saw that her head was twitching. I started to worry that she was having a small seizure until her whole body started squirming around too. I pretty much realized at that point that it was a full-blown seizure and called the vet (that's a lie. I was crying hysterically so my boyfriend called the vet) they said to bring her in. After that, I called my friend who has a lot of reptile experience and asked him what to do. He told me that my best option was to make her comfortable because chances of her surviving were very low. I spent a few more minutes with Sandy before deciding that it was too painful to watch and I couldn't let her suffer any longer. We put her in a box and drove back to the vet to do what we had to do. I handed her off and paid the bill before they cleaned her up and brought her for my final goodbyes. About 30 minutes after we left the vet called and asked permission to do a necropsy on her to find out what happened. She said that upon examination she saw a lot of blood in her mouth and wanted to know where it was coming from. I was in shock that she was willing to do that for me for free but I was more than ok with it. I got the call about what she found early the next morning.
The way she explained it to me was that Sandy was gravid but because of her size it used a lot of her energy. Because of the excess energy used, her liver began processing proteins(?) and she developed something called hepatic lipidosis or Fatty Liver Disease which pretty much means that she had fat deposits in her liver. This led to coagulopathy (inability for the blood to clot) which caused her lungs to fill with blood. The rapid blood loss caused the seizure. She assured me that there was nothing that I could've done to prevent everything happening. It was completely internal and there were no signs of any of this happening.
Sandy was dropped of at the cremation place yesterday and I should have her ashes back sometime towards the beginning of next week. I miss her dearly and wish that there was something that I could've done for her. It hurts that everything happened so fast and it's still hard to get it through my mind that she's really gone.
As for Hoss, I think he knows that she's gone because he mopes around his tank and doesn't want to eat. Now that I think about it, that's actually a usual day for him but I still think he knows somehow. He also knows that his mom is sad because when he was sitting on the dashboard a few nights ago he kept gaping at me as if to say, "Smile, mommy! It's ok!" He will be going in for a full check-up with the new vet.
