How can I balance my father's desire to marry and my mother's request not to financially assist him, given their conflict?

If the father needs to marry to keep himself chaste, then it is obligatory for the able children to help him marry, even if the mother refuses. However, if chastity is already attained, then it is not obligatory, but it is commendable to help him, while trying to combine righteousness to both parents. If that is not possible, then obedience to the mother takes precedence.