Actually the do state that Yoncy is a girl in Necropolis!!... here is a quick excerpt fromt he book:
Holding the infant and pulling the small boy by the hand, Tona Criid ran through the burning northern section of the Commercia. The boy was crying now. She couldn’t help that. If they could make the docks, she could get them clear across the river and to safely. But the routes were packed. As fast as refugees came into the hive from the south, inhabitants were fleeing to the north.
“Where we going?” asked the boy, Dalin.
“Somewhere safe,” Tona told him.
“Who are you?”
“I’m your Aunt Tona.”
“I don’t have an aunt.”
“You do now. And so does Yancy here.”
“Yeah, whatever. Come on.” Tona tried to thread them through the massing crowds that filled the transit channels down to the docks, but they were jammed tight.
“Where are we going?” asked the kid again as they sheltered in a barter-house awning to avoid the press.
“Away. To the river” That was the plan. But with the crowds this thick, she didn’t know if it was going to be possible. Maybe they’d be safer in the city, under the Shield.
The baby began to cry.