I'm sorry you lost her! It's really hard to lose one. I've only dealt with cocci once. Two 4 month old doelings both got sick shortly after I got them. Both had very runny, smelly diarrhea that was dark brown & dark greenish brown in color. At first we thought it was a reaction to the change in food so we waited a day, but by the next day there was no improvement and they were noticibly less active so we took a sample in. The vet prescribed Albon and we noticed an improvement after just one dose. I also keep Sulmet on hand but have never needed to use it. I know others have had very good results with it, though. My vet recommends dosing the meds orally rather than adding to water, to make sure they get the right amount.
I've never had a goat with e-coli so I don't know much about that, but I believe it can take them down pretty fast also. Maybe someone else here knows more about that.
Ivomec is good wormer but it doesn't get tapeworms. I used to use it on all my goats until a fecal showed tapeworms even though I worm regularly. My vet recommends using Valbazen on my goats except when they are pregnant. It's not a bad idea to take a random fecal in for testing every few months, just to make sure you are hitting everything with your wormer, that way if there is something that your wormer doesn't cover, you can catch it before it becomes a problem. I'm not big on pumping animals full of medications and wormers if they don't need it, but parasites can really take them down, and my goats are pets so it's hard to see them get sick.