How can one reconcile the wife's right to sexual intimacy with a lack of attraction to her after her body has changed, especially with the presence of another younger wife, while also considering the feelings of the first wife?

Justice between wives is obligatory regarding maintenance, clothing, housing, and overnight stays. As for emotional inclination, a person does not possess control over it. Allah the Almighty said: (And you will never be able to do justice between wives, even if you should strive to do so. So do not incline completely [toward one] and leave her [the other] hanging) [An-Nisa:122]. The inclination meant here is emotional inclination, and one must not overdo it so that the other wife does not become like one left hanging.

Justice in sexual intercourse is not obligatory, but a woman has a right to it. Scholars have differed on the obligatory amount of sexual intercourse: - Ibn Hazm and the majority of scholars: A man must have sexual intercourse with his wife once every period of purity if he is able. - Ash-Shafi'i: It is not obligatory for him, because it is his right. - Ahmad: Estimated at four months, by analogy with the right of the mooli (one who swears not to have sexual intercourse with his wife). - Al-Ghazali: He should approach her once every four nights, or according to her need for chastity.