Answer:
La hermana pequeña de Marianela.
Explanation:
To respond to the question asking "who is Rosa?", it's necessary to review the entire text. In English, the dialogue translates as follows:
Gabriel: Hi Marianela, what’s up, how are you?
Marianela: I’m good, how about you? What are you up to?
Gabriel: Not much, just hanging out here with the guys. And how is Rosa?
Marianela: Oh! She's my little sister. Take good care of her!
Gabriel: Me? No way! Your little sister is really cute but quite little.
Marianela: Just a heads-up, it would be really bad if anything happened to her.
Gabriel: No worries! All good. Friends?
Marianela: Friends.
Who is Rosa?
Marianela's friend
Gabriel's sister
Gabriel's girlfriend
Marianela's little sister
This shows that Rosa is Marianela's younger sister as per the text.
