Is a married, working daughter obligated to give her father a portion of her salary, especially if it barely suffices to cover her family's debts and her husband's treatment costs, and her father is known for his materialism and for seizing the money of her mother and sisters?

You must be dutiful to your father and treat him kindly, and advise him gently and politely regarding any forbidden acts he commits or obligatory duties he neglects. That is part of being dutiful to him and among the best acts of drawing near to Allah. The Messenger of Allah, peace and blessings be upon him, said: "The father is the middle gate of Paradise, so if you wish, neglect this gate or preserve it."