In addition to his children with his wife, Sir William Wilde was the father of three children born out of wedlock before his marriage: Henry Wilson, born in 1838, and Emily and Mary Wilde, born in 1847 and 1849, respectively, of different parentage to Henry. Sir William acknowledged paternity of his illegitimate children and provided for their education, but they were reared by his relatives rather than with his wife and legitimate children. Emily and Mary both died in 1871 following a Halloween party at which their dresses accidentally caught fire.