Let's condense things down to their essentials. But first, I wanted to share with you that the lady who cleaned our house when I was a child was named Ruby, and she was such a God-fearing sweetheart that I'll give your post my utmost attention, out of respect for her!
And you.
A year and a half is more than long enough to establish the longevity of a client-contractor relationship.
I am dumbfounded this is coming out now, after a year and a half of, what - monthly interaction? Something's not adding up, here...
If you were to write her at all, I'd begin with how hurt you felt about her remarks with respect to her children. I would not embellish or try to justify your hurt, as that usually only serves to give others more ammunition. If you were hurt by her remarks, you were hurt by her remarks. Let her fill in the gaps - if she fills them in correctly and comes to a good conclusion, all the better. If not, then she's not singing on the same sheet of music and it's time to get that out in the open.
None. Then again, with teens in the house, there could be other things going on, as well, including "cutting," an all-too-prevalent practice these days among teens.
It's people's right to dislike weapons as much as it's our right to choose to use them properly.
Probably not, but that her and her husband's choice, and all choices, be they good or bad, have consequences.
Unless she does a 180 in thought, and soon, that's probably the best choice. Should you choose to write a departing letter, I'd keep it short, simple, to the point, and most importantly, non-accusatory, as a bad revue goes much further around the block than a good review. Something simple, like:
"I regret to inform you I will no longer be able to clean your house. I've thoroughly enjoyed working with you and your family over the past year and a half, and hope you have found my work of sufficient quality to recommend me to another household requiring my services."
You shouldn't mention OC/2A rights in closing. She'll know why, and since she's already let you know that they "really like your work," you'll be putting the matter back in her court, and without having to mention a thing. If she capitulates, you're back in their employ. If not, at the very least you won't have ticked her off and she may at least be willing to help you find another customer.
If she doesn't respond at all, smile bravely, hold your head high, and carry on.