Terrible Situation
You didn't say what state you were in, but in my state any theft over the amount of $50 is a felony. Also, your grandmother needs to press charges even if the perpertrator is your sister. She wouldn't be doing her a favor in the long run by letting this just be forgotten even if it is her own granddaughter. She needs to be taught a lesson. Theft is a crime no matter if you steal from your grandmother or a total stranger.
Byu
Truly great madness cannot be achieved without significant intelligence.
Henrik Tikkanen