When I was a kid I stole some money from several of my relatives. Now, Al-Hamdu Lillah, I am praying and want to repent. I want to give them back their money, but without their knowledge, because I feel very ashamed of my act. What should I do? By the way, I can only approximate the amount of money I took from some of them, so I do not know exactly how much I need to repay, but I am willing to give back a considerable amount to resolve this matter.

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

Whoever steals something before reaching the age of puberty is not made responsible for it in Shariah.  Abu Dawood reported that the Prophet (Sallallahu Alaihi wa Sallam) said: "The pen is lifted (prevented from writing the sins) of three people: the child until becoming mature, the sleeping person until waking up, the mad person until recovering."

However, the stolen objects must be returned to their owners in the way that one thinks appropriate and suitable.  In this case, the person is not asked to tell them that he stole something from them.  It is even recommended that he conceal himself.

To conclude, you should now return what you took to its owners.  If you cannot determine it, give what makes you feel that you have indeed returned – at least – what you took.

As for how to return it, this depends on the different situations.  When you give back something you can make believe that it is a gift or something you borrowed sometime ago, or you can send it to them through a third party without them knowing about your past.

Allah knows best.