[ASA Vet]

first generation American of Puerto Rican heritage

Puerto Ricans have been Americans for a lot longer than one generation.

[Onelifetogive]

Puerto Ricans have been Americans for a lot longer than one generation.

How do I say: "She is the first generation born on the mainland." (English as her primary language, not Spanish)

There is a distinct Puerto Rican culture...she is the first generation to be of it.