Is it permissible to take zakat from my mother's money without her knowledge, due to her disapproval? And is she required to fast Ramadan, knowing that she fasted it but sometimes broke her fast, and is she required to offer expiation by feeding the poor? And what should I do with the money she bequeathed for building a mosque, or for charity, or for leaving it?

If the woman is sane, she must be advised and taught to perform prayer (salat) and pay zakat (definition), while clarifying the gravity of neglecting them. It is not permissible to disburse zakat from her wealth without her knowledge, because intention (niyyah (definition)) is a condition, unless she is of unsound mind.

Fasting (sawm) is obligatory for her if she is able. If she is unable due to an impediment that is expected to be temporary, she should make up the missed fasts (qada'). If her inability is permanent, she should break her fast and feed a poor person for each day.

Her wealth is to be spent as she chooses. If she commanded a charity (sadaqah (definition)) but then retracted before the poor person took possession of it, her wealth returns to her.

However, if she is of unsound mind, she is not held accountable (mukallaf), and zakat must be disbursed from her wealth because it is a right of the poor. Her wealth should be safeguarded and spent only for her benefit.