i sincerely hope that you can maintain a peaceful outcome in all of this, we are all on our journey, people like you and myself, are like sponges, we absorb others negetive energy, when you feel that she is going to start this if she does again with you , do a bit of distraction, i worked around people with dementia for quite a while, and we used tactics to distract their behaviour, something like i am going to have a cuppa coffe, or anyone want to have a look at the garden, change the subject in a subtle way, protect yourself, imagine a pain of rose colored glass sheild around yourself and her, i wish you all the very best and it will settle, focus upon you and your family and dont let anyone walk all over you, you are a beautiful being of light.