age of reason

On September tenth — the morning of my seventh birthday — I came downstairs to the kitchen, where my mother was washing the dishes and my father was… reading the paper or something, and I sort-of presented myself to them in the doorway, and they said “Hey! Happy birthday!” And I said “I’m seven.” And my father smiled and said “Well, you know what that means, don’t you?” And I said “Yeah… that I’m gonna have a party and a cake and get a lot of presents (?)” And my dad said “Well, yes, but more importantly, being seven means that you’ve reached the age of reason, and you’re now capable of committing any and all sins against God and man.”

Since the Church has traditionally understood the age of reason to be seven years old, your daughter would not be too young to receive confirmation at age eight.