Praise be to Allah.
The basic principle with regard to women is that when a woman gets married she should stay in her husband's house. Allah, may He be exalted, says, commanding the wives of His Prophet (blessings and peace of Allah be upon him), who are the best example for all women (interpretation of the meaning): “And stay in your houses, and do not display yourselves like that of the times of ignorance” [al-Ahzab 33:33].
Al-Qurtubi (may Allah have mercy on him) said:
The meaning of this verse is the command to stay in the house. Although it is addressed to the wives of the Prophet (blessings and peace of Allah be upon him), other women are also included, even if there were no specific evidence to include all other women. So how about when sharee‘ah is filled with evidence that women should stay in their houses and avoid going out except when necessary, according to what we have stated above in more than one place.
End quote from Tafseer al-Qurtubi (14/179)
Ibn Qudamah (may Allah have mercy on him) said:
The house or home may be ascribed to the one who lives there as it may also be ascribed to the one who owns it. Allah, may He be exalted, says (interpretation of the meaning): “And turn them not out of their homes” [al-Talaq 65:1], i.e., the houses of their husbands in which they live. And Allah, may He be exalted, says (interpretation of the meaning): “And stay in your houses” [al-Ahzab 33:33].
What usually happens, of a woman going to her family's house at the beginning of the postpartum period, is something that is acceptable according to sharee‘ah. There is no doubt that at the beginning of the postpartum period, a woman cannot look after herself properly, let alone look after her husband and take care of her house.
But this should be done with her husband's approval and permission to leave and go to her family's house. If the husband does not give permission, or she knows that he will be upset by that, then she does not have the right to leave without his permission. In return, he does not have the right to overburden her with tasks that are too difficult for her during this period. Rather he has to call her family to come to his house to look after their daughter, if that is possible, or he should bring someone from his family or someone else, even if he has to pay for that, to look after her and take care of her. If that is not possible, he has to help her himself and make up for what she is missing out on of comfort and care from her own family.
If the husband gives her permission to go to her family’s house, as husbands usually do, then the wife has to pay attention to her husband’s rights over her. So she should not stay in her family's house unnecessarily, and she does not have the right to stay there for the entire postpartum period, unless her husband agrees to that. It is well known that many husbands cannot be apart from their wives for this entire period; rather the husband needs her, as any husband needs his wife; even though it is not permissible for him to have intercourse with her during this period, he can still enjoy her in ways other than intercourse.
It is also well known that the woman can look after herself and carry out some of her household duties before the end of the postpartum period. This varies according to the woman’s state of health and the type of birth she had.
To sum up:
If the wife goes to her family's home, there is nothing wrong with that, especially if there is a need for it. But she has to ask for her husband's permission, and if he gives permission, she should not stay away from her house any longer than the length of time for which he gave permission. She also has to pay attention to his rights and his need for her.
And Allah knows best.