Complex sentence: She was the daughter of Pavel Pavlovich Demidov, 2nd Prince of San Donato and his second wife Princess Elena Petrovna Troubetzkaya-her father was the son of the Swedish-Finnish philanthropist Aurora Karamzin and her Russian husband Pavel Nikolaievich Demidov.
Split into simpler sentences: She was the daughter of Pavel Pavlovich Demidov, 2nd Prince of San Donato, and his second wife, Princess Elena Petrovna Troubetzkaya. Her father was the son of the Swedish-Finnish philanthropist Aurora Karamzin and her Russian husband, Pavel Nikolaievich Demidov.