What pronoun would I use when.....

Talking to a stranger who is older than u

Usted

Talking to your friend

Tú

A girl talking about her female friends

ellas

Talking to a group of guys in Mexico

ustedes

talking to a group of girls in Mexico

ustedes

Talking to a group of girls in Spain

vosotras

Talking to a group of guys in Spain

vosotros

Talking about a boy

él

Talking about a sister

Ella

talking about a group (con chicas)

Ellas

Talking about a group ( con chicos y chicas)

Ellos