Is the money inherited in the bank account in the questioner's name, and the lands that were gifted to her and registered in her name before her mother's death, considered her property or part of the inheritance that the other heirs have the right to claim?

The financial support (nafahqa) of a sister by her brother is not obligatory except under certain conditions, including her poverty, her inability to earn a living, and her brother's wealth and his being an heir to her. Otherwise, it is not obligatory. Some scholars, such as Imam Malik, are of the view that it is not obligatory at all.

The land that the mother registered in your name as a gift and that you took possession of before her death is yours alone, excluding the other heirs, even if the mother sinned by preferring you unless there was a legitimate reason. What the mother gifted during her health and sound mind, and possession of which was taken, becomes binding after her death, and the heirs have no right to revoke it.

Regarding the money in your name at the bank: if it belonged to the mother and she deposited it with you, then it is an inheritance to be distributed among the heirs. If it was jointly owned by you and your mother from what you inherited from your father, then the mother's share is added to her estate, and your share is yours. If all of the father's inheritance of money was placed in your account without the involvement of the other heirs, then it must be divided according to Sharia.

Disputes must be referred to the Sharia courts for resolution.