The ruling on returning lost money from a trust

Question:
May Allah reward you with good and do you good. She says: One of the women placed a trust in my hands, and when she wanted to retrieve it, she found that it was short by five hundred dinars. I did not know the number of coins she had placed, but after arguing and discussing, she said it was possible that she had made a mistake in the count and left. However, after a long time had passed since she took it, my sister came to me and told me that she had been taking money from me, and she did not know the amount of money she had taken. Her age at that time did not exceed five or sixteen years old, and she is now twenty-two years old. She is very remorseful about her action and does not know what to do now. She is currently committed to the religion in a good way. May Allah reward you with good.

Answer:
You are entrusted with this matter to preserve it. Is it not permissible to be negligent in it and allow someone to take from it? Rather, it must be locked in a secure place and kept safe. So, you are negligent based on the apparent meaning of your question? Your sister, who has reached maturity and knows, must return this money through you; she should give you this money and you should return it to the owner of the trust. Your conscience and your sister's conscience will not be cleared except by doing so, unless the owner of the money permits it and forgives this missing amount.