14 years, 8 months.

Dear Jack,
As I was finishing up washing the dishes in the kitchen, I heard you and your sister laughing in the dining room.
You took it upon yourself to make ice cream sundaes for the two of you. Apparently what caused the laughter was that you accidently gave her way too much whipped cream; to the point there was more of it than there was ice cream.
This really is becoming the norm: That you find ways to help and serve your sister, which often leads to the two of you laughing together and having fun.
It is such a reward as a parent for me to see this development.
Love,
Daddy