All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
You should remind this girl that stealing people's properties is a grave major sin and that she will never be rewarded for helping those people with that stolen property for it is ill-gotten and Allaah, the Exalted, accepts only what is good. The Prophet, sallallaahu ‘alayhi wa sallam, said: "Allaah Almighty is good and accepts only that which is good." [Muslim] The fact that she gives the stolen property in charity is not an excuse for committing theft. You should also remind her that she needs to turn to Allaah, the Exalted, in repentance and give back all that she has stolen from others or seek their forgiveness before the Day of Judgment, when no property will avail her. To have the urge to help others and the keenness not to turn down those in need are good qualities, but this should not be a pretext to do what is unlawful. Moreover, if she wants to give in charity but cannot afford it, she will be rewarded for her good intention. The Prophet, sallallaahu ‘alayhi wa sallam, said:
"The similitude of the people of this nation is like four individuals. One whom Allaah, the Exalted, has given wealth and knowledge, so he handles his wealth with knowledge, spending it rightfully. One whom Allaah, the Exalted, has granted knowledge, but not wealth, and he says, "Lord, should I have wealth like such-and-such, I would have handled it like him." They both have the same reward. (Then there is) another man; Allaah has given him wealth, but not knowledge, and he spends his wealth unrightfully. And (finally) a man whom Allaah, the Exalted, has granted neither knowledge nor wealth, but he says, "Should I have wealth like such-and-such, I would spend it in the same way that he does." So, both are equal in sin." [Ahmad and Ibn Maajah with an authentic Isnad]
Allaah Knows best.