"I'll answer them one by one, and the least important first.

How I know your name is my own secret; I can't tell that without telling also what would crush you.

But I may as well say that I know all about you.

I know your appearance, and your age, and even a little bit about your character; and I know you have a younger sister called Mabel, and that she is not so pretty as you, and has not half the character, and in short that you are worth two of her.
"Then you have a brother.

His name is Loftus.