García is a surname, so it can refer to any personal pronoun:
Ustedes los García
Los García (ellos)
The subject pronoun for "mi amiga" in Spanish is "ella", which means "she" in English.
When talking about your grandmother in Spanish, you would use the subject pronoun "ella" (she).
You would use the subject pronoun "tú" when talking to a young girl in Spanish.
If I understand you correctly, the answer is 'she'. That is the 3rd person singular feminine subject pronoun.
The subject pronoun for "tu amigo y tú" is "ustedes" in Spanish.
"Hermano" means "brother," so the subject pronoun would be "él," equivalent to "he."
Two boys? You could say ellos, which means they.
él
The subject pronoun YO is not accented
The subject pronoun "usted" is used to talk to a police officer in Spanish as a sign of respect. It is the formal way of addressing someone in a position of authority or someone you are not familiar with.
"Es" is a Spanish pronoun which means "it" or "is." It is often used as a subject pronoun in sentences to refer to a previously mentioned noun.
"Somos" is first person plural, or "we". You would use "nosotros" with it.