So my best friend thinks that i stole thousands of dollars from her but i didnt. What do i do? (were 15 years old)
At 15, she had that kind of money? Well until she proves it, she can't blame it on you.
I agree with @Russianrespect. And she or he is that young with that kind of money.
Show her that you didn't stell enything from her in smart way ?