Answer: 7 regional dances.
Explanation: The question says:
"How many regional dances does Amalia Hernández's folk bunch have?"
The Ballet folklórico of Amalia had more than 60 plays, most of them composed by her, about the dances as a "type of dance" the ones included in the ballet are:
Los Matachines, Guerrero-Guerrero, La revolucion, La Charreada, Danza de los Quetzales and Danza del Venado, so there are 7 regional dances in the ballet.