I don't mean to sound callous, but shit happens, especially with pets. Dogs are notorious for eating things they shouldn't, I assure you a dog could find something to get in to that they shouldn't and that could harm or even kill them even in the tidiest house.
Now if you'd said you didn't take her to her appointment, or didn't even call the vet, I'd have some harsh things to say, but you reacted and acted appropriately to an accident.
You did the right thing in a difficult situation, try not to beat yourself up over it or hold yourself up to an impossible (read: neurotypical) standard (easier said than done, I know), and be there for her as she recovers.
You're welcome, and remember that they're for browsing, not necessarily consuming in bulk, some of them I've never read the whole way through, but they provide answers to specific questions and are great for dipping in and out of.