The younger sister Mary Elizabeth married, in June 1890,[3] a German nobleman, the Baron von Zedtwitz, a Lutheran, and since then left the Roman Catholic communion.

[6] The baron and his wife Mary Elizabeth had one son, Waldemar Konrad von Zedtwitz,[4][7] a future bridge champion.

[8] Mary Gwendolin Caldwell was accounted a Kentucky beauty and heiress, her mother being one of the famous Breckinridge family of that state.

On their return to America, Gwendolin went to Louisville, Kentucky, rented an entire floor of the Galt House, and prepared to entertain in a manner new to the people of that place.

[6] For this service Pope Leo XIII bestowed upon Gwendolin Caldwell a diamond-studded medal, which he had struck especially for her, and also conferred the decoration of the Order of the Rose, which distinction no other woman ever had held.

[6] The young heiress went to Italy in 1887, and there met Joachim, 4th Prince Murat, who was thirty-three years her senior, and deeply in debt.

[6] After their engagement was announced preparations for a regal wedding were made, a trousseau said to be "fit for a queen" secured, and the day for the ceremony set.

[6] Bishop Spalding of Peoria, when asked if he could assign any reason for the Marquise des Monstiers' action, he answered that he could not; that he knew her only as a good Roman Catholic, and until the announcement was made had given no thought otherwise.

[13][14] Mary Gwendolin told her sister in 1901 that she had been sexually involved with Spalding for twenty years, beginning when she was nineteen.

"[15] In 1905 the Marquise and the Marquis separated, but she agreed to pay him an annual stipend of $8,000 in order to avoid a divorce and retain her noble title.