I am a Spanish citizen and I live in the USA. My daughter is a minor, she is in Cuba, what do I have to do so that she can obtain a Spanish passport in Cuba, what should I do from Haquy and how

The first thing would be to ensure that she acquires Spanish citizenship through you, I recommend that you refer to the Spanish Consulate in Miami or in the place of the United States where you reside for guidance on the procedures to follow. You can follow this link http://www.exteriores.gob.es/Consulares/MIAMI/es/ServiciosConsulares/Paginas/SCMiami/Nacionalidad.aspx

I recommend calling the Spanish consulate for better information.