diabla and rosa are (or used) to be siamese twins, however, due to their parents seeing this “deformed demon girl” (referring to diabla) conjoined on rosa’s body, they immediately had the surgery done and was going to throw her away somewhere to basically rot and die, they did not want the “other one” (that being diabla yet again) to ruin the beauty of their now favorite daughter. however, the grandmother basically had them give her the child in which the baby girl was named “diabla”, a name that is the feminine version of “diablo”, it translates to “devil” or in this case, “she-devil”.