I got accused of taking money when i didnt?

So my sister is accusing me of stealing money from her and is telling me shes going to tell my parents and stuff and i know my parents will believe her and punish me, so how can i convince my parents i didnt do it? I honestly didnt, she misplaced her money and is blaming me for taking it. I have only birthday money and thats hidden in my room, so i dont know where she thinks im keeping or what im doing with it. I dont really use small amounts of money cuz i save up money, and she thinks i took like 5 bucks from her and her birthday money thats 25 bucks. I really didnt take it and im so angry that shes accusing me!! Please tell me what to say to my parents and how to let them know i didnt steal it?