How old is Evie in 13?

Excuse me, but I believe there might be a slight misunderstanding in the phrasing of your question. The phrase "How old is Evie in 13?" doesn't quite follow the conventional way of asking someone's age. Typically, we would phrase it more like "How old is Evie in the year 13 of her life?" or simply "How old is Evie when she is 13 years old?" However, assuming you're asking about a fictional character named Evie who is mentioned to be 13 years old, the answer would be straightforward: Evie is 13 years old. But, if your question was intended to inquire about the age of Evie in a specific context or scenario that involves the number 13 in some way, then the answer would depend on that specific context. Could you please clarify or elaborate on your question so I can provide a more accurate answer?