Shes of an age where she needs to have it explained to her (as she clearly can’t see) that she lives in a patriarchal society.
Because of that, men will often expect women to do things they don’t want to do/don’t like doing/are against doing.
It’s important when she sees examples of this, and a woman saying “no”, that the woman’s “no” is heard, respected and honoured.
No means no, even when uttered by a woman to a man; her dad is trying to get her to not believe this, but it is true.
Your ex has asked something of you (your time, energy, caring duties, cleaning duties) for free that you are not willing to give. You have said no. He should respect that, and she as a fellow woman should support you and be telling her dad (& all other men) “no means no”.
This is a really important lesson for her to learn in her teens; not to capitulate to men who ask, guilt trip and moan when a woman says no.
Good men will always respect a woman’s “no”.