Are Melanie Rios and Valerie Rios sisters?

Answer 1

No, they are not.

Melanie Rios was born in Colombia as Sara Vélez Galeano on April 8, 1991.

Valerie Rios was also born in Colombia. Her birth name was Jessica Alejandra Urrego and she was born on 12 December 1990.

While it undoubtedly adds to the "naughty" content of scenes they do together, there is no real indication that there is a blood relationship between the two. They may well have come to the US together and may consider themselves as "sisters" but in the biological sense of the word, they are not.

I consider the original answer (below) to be incorrect and the product of marketing hype.

[--- begin original answer ---]

I've read their bio, where they admit they are sisters. They came to the US from Colombia a little more than 2 years ago. Melanie specifically states: "I moved to L.A. with my sister and best friend Valerie to get into acting and modeling..."

[--- end original answer ---]