I've heard of some pair girls who had some success in that discipline but later gave it up because they really didn't enjoy being 10 feet off the ice, getting thrown up in the air, etc. It definitely takes a daring personality to enjoy the danger.
Families can also play a role. Some siblings do ice dance, some do pairs. Dylan Moscovitch used to do pairs with his sister Kyra. The Boys-Eddy siblings from Brampton decided to do pairs because of their height difference. And it also runs in the family for Isabelle Brasseur. Her daughter, Gabriella Marvaldi, competes in junior pairs in the US. Her niece Justine Brasseur is a pair skater in Canada.