Accepting money as a gift that was supposed to be given in charity

1. My mother wants to offer me her money which she says is earned by halaal means by selling her land. However, I have a doubt in my heart that the money is actually not halaal as it is charity collected from people that was supposed to be given to the poor and needy. Is taking this money from my mother permissible for me?

2. I want to start a business using this money, but because I have a doubt about it, I want to keep only the profits and pay back all of the invested amount to my mother. Will this be permissible?