Final answer:
The subject pronoun in Spanish for two girls is 'ellas' which means 'they'.
Step-by-step explanation:
The subject pronoun that you would use to talk about two girls in Spanish is ellas. It is the equivalent of 'they' in English. For example, you could say 'Ellas son de Oregón' to mean 'They are from Oregon' or 'Ellas son de California' to mean 'They are from California'.
Learn more about Subject pronouns in Spanish