The reason birds don't get electrocuted whenever they sit on wires is because they are on only one wire at a time. If they were to be on both wires at the same time they would essentially be ready to eat by the time they hit the ground. That said is porcelain a conductor or an insulator? Just curious.

"Its high resistance to the passage of electricity makes porcelain an excellent insulator." is what the Wikipedia page says. So yes, Suigintou would be fine sitting there, but I'm not so sure about her clothes.