Fifteen

Apparently, and according to Nana, 15 is kind of a big deal for a girl. 
15 for a girl is the equivalent of 18 for a boy. Or 23 for Finn. Or 32 for Luca. 
15 is no longer a girl actually, but a young woman. 
15 is also the age Nana was when she met Pepe Jean-Claude (married 3 years later, and mother to a little Raheny_Eye one year after that, so no pressure there Mimi!) 

It is great to see turn into the woman that you are, and will be. Wise, self-assured without being cocky, organised and hard working (when it comes to school), messy and verging on lazy (whenever it is to do with housework or anything that Mum or Dad can do for you), funny and sociable and most of all very well read. 
You're dead right. Pack them in, all these books. For people are the sum of the books they've read, the experiences they have accumulated, the mistakes they have made, the lessons they have learned. 
You are already wise beyond your years. Each year I say that. Each year you manage to stay ahead of the curve. 
You are a delight to have around the house. Your brothers won't contradict me. 

You could just perhaps tone down the sarcastic remarks aimed at the older generation. 
I wonder where you got that from. 
Your mother I guess...