All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
You are not Islamically obliged to take back your wife and you are not sinful if you do not take her back. As regards whether or not taking her back is good for you in this worldly life and in the Hereafter, then we cannot authoritatively assert either of them. What we advise you to do is to look into the matter of accepting her request but you should not hasten to accept or to refuse. Rather, you should take your time and seek the advice of trustworthy and rational people who know her among your relatives or hers. After seeking consultation from people, you should perform the Istikhaarah prayer and Allaah will predestine what is good for you, Allaah willing. For more benefit on the Istikhaarah, please refer to Fatwa 81434.
It should be noted that it is not permissible to take back a wife whose waiting period has expired except with a new marriage contract. For more benefit on the kinds of divorce, please refer to Fatwa 82541.
We would like to draw your attention to the following matters:
1- The wife has the right to a separate accommodation and she is not obliged to live with her in-laws. However, it is desirable for her to have good relations with her in-laws whether she lives with them or far from them, as this leads to the love and kindness of her husband. What is meant by accommodation here is to prepare for her a room with its separate amenities, like the kitchen, bathroom and hallway. It is also a condition that the accommodation suits the women of the same social status like her. Hence, if the husband provides his wife with such accommodation – even if it is within a shared accommodation – then the wife has no right to refuse; rather, she is obliged to obey her husband.
2- She has the right to ask her husband to spend on her, but it is not permissible for her to interfere in him spending on his parents or being kind to any of his relatives.
3- On one hand, the husband is not obliged to live where her wife lives; he has the right to leave her in a safe and secure accommodation but he should not be absent from her for more than six months. On the other hand, the wife is obliged to move with him wherever he resides unless she had conditioned on him before the marriage contract that he should not take her out of her town, in which case, he is obliged to fulfill her condition.
4- It is Islamically required that the spouses should have good marital relations and the wife should know the status of her husband and she should not look down upon him, and she should not disobey him in what is permissible otherwise she is considered a recalcitrant wife. For more benefit on how to treat a recalcitrant wife, please refer to Fatwa 85402. Of course, divorce is not the first step in treating such a wife.
5- It is not appropriate for a wife who prays five times a day and wears Hijab to have such a bad moral character. The effects of obedience appear in the conduct of the Muslim male or female, as his (her) soul becomes pure and his (her) conduct becomes good; Allaah Says (what means): {Recite, [O Muhammad ], what has been revealed to you of the Book and establish prayer. Indeed, prayer prohibits immorality and wrongdoing.}[Quran 29:45]
6- Fostering a child and being kind to him is an act by which one gets closer to Allaah, but adoption is forbidden, and so, it must be avoided as clarified in Fatwa 82371. Allaah Says (what means): {And He has not made your claimed [i.e. adopted] sons your [true] sons. That is [merely] your saying by your mouths, but Allaah says the truth, and He guides to the [right] way.}[Quran 33:4]
7- You should marry a prolific wife hoping that Allaah will bless you with a righteous progeny.
Allaah Knows best.