Why aren't the prayers of a wife answered when she supplicates to God every night for her husband, who abandons her for months at a time, to have intercourse with her?

A servant must supplicate to his Lord while fulfilling the causes and conditions for the supplication to be answered. Allah Almighty has promised to answer the supplicant, as He says, "And your Lord says, 'Call upon Me; I will respond to you.'" His response may be according to His knowledge and wisdom. He may respond to the supplicant in one of three ways, as mentioned in the Hadith: "Either his supplication is granted to him expeditiously, or it is stored for him in the Hereafter, or an equivalent amount of evil is averted from him." The husband must engage in coitus with his wife according to her desire and his ability, and it is not permissible for him to abandon coitus if she is harmed by it. It is advised to have a good understanding with the husband regarding the rulings of coitus, and a wife adorning herself for her husband has an effect on enticing him and inviting him to coitus.