Is a son's pushing his father away from his mother while the father was hitting her, having previously wished death upon him, considered disobedience to parents, knowing that the father died pleased with his son?

What the father was doing was clearly wrong, but it does not justify disloyalty to him or supplicating against him. Rather, he should have been advised gently and kindly, the حرمة (prohibition) of his action should have been clarified, and help should have been sought from his family and friends, then his matter should have been entrusted to Allah. Since she repented and was dutiful to him, and he died pleased with her, it is hoped that Allah will forgive her, for "The one who repents from a sin is like one who has no sin," and it is hoped that Allah will forgive her father.