What are the attributes of wife’s accommodation?

Is  there any financial obligation on a married daughter to her parents, knowing that she helps them without husband`s knowledge to avoid disputes where she pays them from her own salary, which she uses to coverthe household expenses?

I am a married woman. I had to work because my husband can`t afford our basic needs. After I got the job, my mother-in-law started asking me for money. Recently, she asked me to help with the marriage expenses of my brother-in-law. Moreover, my husband and I live in a rented house and he is liable for several debts. Is what she is asking of me permissible from an Islamic perspective?

Is it lawful to give the Zakah of my money to my brother for whom I already provide?

Is the daughter who receives a salary obliged to provide for her father?