She had had a guardian, a soft, woolly, comfortable gentleman whose will she had brushed aside and replaced by her own from the time she was eight years old.

Legally, she was not of age till twenty-one; in reality, she was of age at fifteen or thereabouts.

She consulted Colonel St.John, her guardian, about her affairs, as an act of grace, because she was so fond of him and wouldn't hurt his feelings for anything; but she made no secret of the fact that at twenty-one she was going to be absolutely her own mistress.
"You are your own mistress now," Colonel St.John said once, a little ruefully.

"You never do what I wish--you make me do what _you_ wish.
Don't go too fast, Agatha, my dear.

At twenty-one one is not wiser than old people, though one may feel so." But he knew that he was talking to empty air.