Sorry you had to deal with all of that.
Unfortunately I see a lot of ways that much of that could have easily been avoided. Several mis-steps on both sides.
It's understandable as to why those that care for only a couple children feel as if they don't need a contract or written policies but it's always been advised to have a written contract as well as a written set of rules between you and your client or clients if any money changes hands.
Like I said, I am sorry you had to deal with such a dramatic situation but I see fault on both sides and I definitely don't think this is all on the daycare mom. The good news however is that any time you end up dealing with something like this you learn what not to do or what you must do differently the next time.
