I don’t know what you meant in the first sentence but I think I can make sense of it. 1: how old were you when I was 5 years old? 2: I liked to play with my friends when I was young. 3: who did you play with when you were in primary school? 4: where did you go with your friends when you were young? 5: you’re the funniest of your friends 6: my sister is 5 years old and she likes to read, what did you read when you were 5 years old?
** I am fluent if mexico spanish not spain so they may have different meaning of words but they shouldn’t be too different so these should be right.
Because "esas" means them/they, but in feminine form. So if we translate the sentence it would be: "Those/The girls in the picture are my cousins Malena and Alejandra"
estar is to do with to be when it comes to people being somewhere, something being placed somewhere while Ser has to do with to be as in profession or to feel.