Eleanor was a member of the Long Island, Republican Roosevelts while Franklin was a member of the Hyde Park, Democratic branch of the family. The two branches had peeled off generations before. Eleanor was the cherished niece of Theodore Roosevelt - obviously head of the Long Island branch at the time - because she was the oldest child of TR's younger brother Elliot, who died of alcoholism and other ailments when Eleanor was a girl. It was President Theodore Roosevelt who walked Eleanor down the aisle.
Eleanor and Franklin had 6 kids together (5 that lived into adulthood) but after the late 1910s they no longer really lived as man and wife: they loved each other but didn't really have romantic involvement with each other anymore.