Is a daughter's request to her father to rent a house for him and his wife—given their financial capability—so that she and her children can live alone, considered an act of disobedience or a right for her?

It is not obligatory for a son to house his parents if they are wealthy. However, it is advisable to treat them with kindness and filial piety, as stated in the Almighty's words: "And to parents, do good" and "And We have enjoined upon man, concerning his parents, good treatment." The Prophet (peace be upon him) exhorted kindness to the mother three times, then to the father, and he made filial piety one of the most beloved deeds to Allah after prayer, stating that Allah's pleasure is from the parents' pleasure and His displeasure is from their displeasure. Housing the parents with the son might be more comfortable for them if they need assistance, and it would be easier for the son to fulfill their rights, unless the house is cramped.