Sakuya teases Nagi explaining that she is so bratty that she can't take care of young children. Furious, she asks Hayate to go out and find her kids to take care of.
They're apparently on vacation 
and became separated from their parents.
Parece ser que estaban de vacaciones 
y se separaron de sus padres.
Aparentemente, elas estão de 
férias e se separaram dos seus pais.