Complex sentence: Queen Victoria's father, Prince Edward, Duke of Kent, was not a haemophiliac, and the probability of her mother having had a lover who suffered from haemophilia is minuscule given the low life expectancy of 19th century haemophiliacs.
Split into simpler sentences: Queen Victoria's father, Prince Edward, Duke of Kent, was not a haemophiliac. The probability of her mother having had a lover who suffered from haemophilia is minuscule, primarily due to the low life expectancy of 19th century haemophiliacs.