Is the money and the devices that the questioner left in her family’s home, and then took without their permission, considered theft or her rightful property, knowing that her mother did not act justly between her and her sister in giving, and is what she inherited from her husband considered a debt to her mother?

If you left money and devices for your mother as a gift and a connection (to maintain kinship ties), then you are not permitted to revoke it; due to the Prophet's (peace be upon him) saying: "It is not lawful for anyone to give a gift and then take it back, except a father from what he gives to his child," and "One who takes back his gift is like a dog that vomits and then returns to its vomit."

However, if what you left was by way of a loan, a trust, or a borrowed item, then you have the right to reclaim it. It is not permissible for you to take your parents' money without their knowledge unless your right is established and you cannot obtain it except by doing so, and under specific conditions.

A mother providing for her daughter when she gets married is not considered a prohibited favoritism if it is done within reasonable bounds, because it falls under the category of spending (nafqa).

Even if the mother's favoritism is assumed, it is not permissible for you to take her money without her knowledge. Rather, it is obligatory for you to return the money you took unjustly, and it is a debt upon you, not upon your husband.