When TR's first wife, Alice, died suddenly, most probably of kidney failure, Bamie took custody of her child of a few days, Alice, quickly known as Baby Lee for her mother's family, the Lees of Boston.
When TR's first wife, Alice, died suddenly following childbirth, most probably of kidney failure (Bright's Disease), Bamie took custody of her infant, Alice. Because her grieving father would not call her by his late wife's name, Alice was called "Baby Lee" for her mother's family, the Lees of Boston.