Do the siblings refuse to financially help their father to please their mother, knowing that the father does not spend on them and possesses what suffices him?

May Allah protect your parents for you and help you be dutiful to them. And we say to your mother: Let your children treat their father well and encourage them to do so, even if the father acts wrongly or falls short, because the father's right is great and it is not permissible to neglect it. The Prophet, peace and blessings be upon him, said: "The father is the middle of the gates of Paradise, so if you wish, preserve it, and if you wish, squander it." The meaning of "the middle of the gates of Paradise" is the best and highest of the gates. Children should not please their father by displeasing their mother, nor vice versa. Rather, each has a right to obedience, and neither should be obeyed if they command neglect of the other's rights.