I've read there were some doubts about the paternity of some of Isabella's children, including Eulalia. I tend to believe that these are untrue, (I mean Eulalia and Paz, from what I can see, had blue eyes, and if their father was indeed one of the alleged Spanish lovers of their mother, they would have much probably inherited their father's brown eyes since blue eyes gene is obviously not the most common gene among Spaniards, with all my respect) however, if someone has more information, I'm interested.