Gabriel: hola marianela, ¿qué onda? ¿cómo estás?
marianela: chévere y tú ¿qué haces?
gabriel: nada, por aquí con los muchachos. ¿y qué es de rosa?
marianela: ¡oye! ella es mi hermanita. ¡mucho ojo con ella!
gabriel: ¿yo? , ¡no manches! , tu hermanita es muy linda pero es muy chiquita.
marianela: bueno, pues yo sólo te aviso, mira que sería muy mala onda si la lastimaras.
gabriel: bueno, todo está chido. ¿amigos?
marianela: amigos
¿quién es rosa?
la amiga de marianela
la hermana de gabriel
la novia de gabriel
la hermanita de marianela

La hermanita de Marianela.

Explanation:

You have to read the whole text and then, you have to answer the question that says "who is Rosa?". In English the text says the following:

Gabriel: Hi Marianela, what's up, how are you?

Marianela: All right and you? What do you do?

Gabriel: Nothing, I'm around here with the boys. And How is Rosa?

Marianela: Hey! She is my little sister. Very careful with her!

Gabriel: Me? Don't stain! Your little sister is very pretty but she is very small.

Marianela: Well, I just warn you, look it would be very bad if you hurt her.

Gabriel: Well, everything is cool. Friends?

Marianela: Friends.

Who is Rosa?

Marianela's friend

Gabriel's sister

Gabriel's girlfriend

Marianela's little sister

So as you can see, the text says that Rosa is Marianela's little sister.

im sorry what are you trying to figure out?