Adult children are responsible for themselves when they assume complete responsibility for themselves. In other words, if your daughter is dependent upon you for education, shelter, and (potentially) health and auto insurance, she is not fully independent, no matter her biological age. So long as she is your dependent, you have the right to insist that she meet her religious obligations.
That said, I think your daughter has a false notion of “freedom.” She seems to think that adult practicing Catholics are free to skip Mass whenever they want. Technically, that is true: There are no Catholic police who will cite absentee Catholics for skipping Mass. But skipping Mass on Sundays and holy days without just reason is grave matter; when done with adequate knowledge and deliberate consent, it is a mortal sin.
What your daughter needs to realize is that becoming an adult does not “free” her from religious obligations; what it does is to free her to assume full adult responsibility for her religious obligations.