What is the correct Islamic ruling regarding the pouch of money that a woman left with her neighbor as a trust, saying to her: "If I die, then take it"?

The action of the deceased woman is a will concerning money, and it is obligatory for the will to be intended for good deeds, not to harm the heirs. If the intention to harm the heirs becomes apparent, the will is void and rejected. Islamic law has defined harm as the testator exceeding one-third of their wealth or intending to harm an heir. So, if she bequeathed more than one-third, or with the intention of causing harm, then the will is rejected and void.