Is silence regarding a father's injustice considered an act of righteousness (birr), and is confronting him about his injustice considered an act of disobedience (uquq)?

Your patience with your father's harm is rewarded, and there is no sin upon you in speaking to him to remove injustice and discrimination between you and your sister. This is not an act of disobedience, provided you adhere to appropriate language and suitable words for a father's position. We advise you to be patient, seek reward from Allah, and supplicate frequently.