Here is something on Ferdinand and his second (morganatic) wife, Lucia:
Ferdinand loved his second wife very much. He wrote her tender letters, which began with "To my dear and good Lucia" and signed off his letters with "Your affectionate companion who loves you dearly". Not only was he tender in his letters but also they were also full of gratitude. Perhaps because she made his last years sweet and cheerful, especially after a lifetime spent at the side of the "unbearable" and "intriguing" Maria Carolina, who was nicknamed by the people as the "Austrian Erinyes". In fact, Ferdinand considered his affair with Lucia as a "miracle".
In addition, Ferdinand (whom MC described as not one to give presents and indeed she never got a even a garden from him, which she greatly desired) was very generous to his 2nd wife and her children (from her first marriage): countless ducats, fabulous jewels (diamonds and parures), a palace and a country villa (complete with a zoo), among others.