Is it permissible for a mother to gift her daughters apartments, one of which was the marital home and the other for rental income, knowing that the circumstances of their husbands vary, with some being of moderate means and others being very poor?

It is permissible for a mother to gift some or all of her property to her daughters, provided there is justice among all children, both male and female, by giving them equally or according to inheritance. It is not permissible to prefer some over others in gifting unless there is a valid reason, such as need, illness, preoccupation with seeking knowledge, or withholding a gift from a dissolute person. This is supported by the hadith of Nu'man ibn Bashir and what was narrated from Abu Bakr al-Siddiq (may Allah be pleased with him).