She had died and left one child.
The second Mrs.Carlyle died when her son was born--Archibald; and his half-sister reared him, loved him and ruled him.

She bore for him all the authority of a mother; the boy had known no other, and, when a little child he had called her Mamma Corny.

Mamma Corny had done her duty by him, that was undoubted; but Mamma Corny had never relaxed her rule; with an iron hand she liked to rule him now, in great things as in small, just as she had done in the days of his babyhood.

And Archibald generally submitted, for the force of habit is strong.

She was a woman of strong sense, but, in some things, weak of judgment; and the ruling passions of her life were love of Archibald and love of saving money.
Mr.Davidson had died earlier than Mr.Carlyle, and his fortune--he had never married--was left equally divided between Cornelia and Archibald.
Archibald was no blood relation to him, but he loved the open-hearted boy better than his niece Cornelia.