What is the ruling on me going to the market with my brother, disobeying my mother who prevents me from going out due to my brothers' refusal, while I have been staying at home for a month?

If a mother prevents her daughter from going out alone with a driver, she must be obeyed, as this constitutes an unlawful private seclusion (khalwa). However, if she prevents her from going out even with her brother without a valid reason, then it is permissible to go out with the brother for a lawful purpose without her permission.