What should a committed girl do who fasts and prays, yet feels guilty because her father does not fast, despite him being kind and affectionate?

If the father breaks his fast in Ramadan without a valid excuse, he is committing a grave sin. However, this does not negate his right to dutifulness and companionship with kindness. He should be advised, warned, and the danger of his action explained gently and courteously, without harshness or violence; for parents are not like others when it comes to enjoining good and forbidding evil.