I cannot believe this woman, what an inconsiderate B****!!
You can't blame yourself either, you aren't responsible for what other people choose to do and she chose to blatantly ignore your wishes in YOUR home. That it led to Ceilidh being hurt is not on you but on her for ignoring you and on Derek for not backing you up.
That she used your dish as an ashtray is just disgusting. It wouldn't matter if you allowed smoking in your lounge, you just don't use any available object as an ashtray, you ASK first.
Sheesh I am fuming on your behalf!!
I hope Ceilidh is OK and gets over this, it would be such a shame for a natural with animals to end up nervous around dogs
Maybe in the near future, arrange for her to spend some time around dogs you know are gentle?