Disciplinarian????? she is 19 and of legal age....and I'm certain that you didn't have sex by the age of 19.....
I’m certain it is legal to have sex at 19, that does not make it right.
It is legal for the federal government to set the tax rate at any level they want, that does not make it right.
I am speaking about her moral responsibilities and her father’s. One cannot say she can run around and do what ever she wants and dad has to accept it. If he has a moral responsibility to respect her she has a moral responsibility to behave.