Must the female questioner return the money she secretly took from her father, knowing that her share of her deceased mother's debt — which is owed by the father — is greater than the amount she took?

If you take from your father's money what suffices your needs according to what is customary, then there is nothing upon you, and you are not required to return it. However, if you take the money without a right, then you must return it to your father. And if your father owes you a debt from your mother's inheritance, then it is permissible to consider this money as part of the debt without informing him or obtaining his consent, as set-off occurs simply by the establishment of the two debts, provided they are of the same kind, type, description, and are due.