Answer:
Anne kept a diary before they went into hiding.
Step-by-step explanation:
When Mr. Frank is reading Anne's diary, he is on the first page of her diary and it says "Dear Diary. since you and I are going to be great friends, I will start by telling you about myself. My name is Anne Frank. I am thirteen years old. I was born in Germany the twelfth of June, nineteen twenty nine. As my family is Jewish, we emigrated to Holland when Hitler came to power"
as that is the first page of her diary, it basically states that she started the dairy after she moved to Holland after Hitler took over germany.