Rio Morales is a capable nurse, a supportive mother to her children, and a dedicated wife. She worries about her patients and family, especially her Super Hero son, Miles Morales, AKA Spider-Man.
Hailing from Earth-1610, hospital nurse Rio Morales marries police officer and agent of S.H.I.E.L.D. Jefferson Davis, and together they have a son, whom they name Miles. Rio enjoys dancing around the house with her son, and when he later becomes Spider-Man, she supports him.
Rio is a skilled nurse and adept at using firearms when defending her patients and family from assailants. As a native of Puerto Rico, Rio speaks fluent Spanish and English.
Rio’s most prominent enemy is Conrad Marcus, AKA Venom, who attacks Brooklyn General Hospital where she works and because of his attack, Rio loses her life.
Rio is most close to her family, including her husband Jefferson, son Miles and daughter Billie, and her mother Gloria Morales. She misses Miles while he’s away at school and hugs him when he visits home. Rio finds out about his alter ego and supports his super-heroics, though she discourages him from telling Jefferson, whose experience with super-powered people gives him a bad opinion of them.
Later, she loses her memory of her son’s identity as Spider-Man. She eventually calls them out on their secretive behavior, and once they reveal the truth, she feels betrayed by them.
With Miles and Jefferson, Rio attends a lottery hosted by the Brooklyn Vision Academy, a prestigious charter school that was only accepting three new students. Out of 700 applicants from their neighborhood, the likelihood of Miles getting chosen seems unlikely, but Rio remains hopeful as two names were called. When Miles' name gets called, Rio and Jefferson rejoice, hugging their son.
After Miles and Jefferson discussed his father’s criminal past, Rio asked Miles how he was dealing with the information. When Miles asked if his father was bad, Rio called his younger self immature and stupid, but not bad and she knew him well after he had put his criminal ways behind him. She defended him, and noted that he was a good man, a changed man. When asked about his Uncle Aaron Davis, AKA Prowler, who was involved in Jefferson’s criminal activities, Rio called Aaron a bad person.
Rio becomes suspicious of her son when he makes loud noises in his room. When a new Spider-Man showed up and Jefferson criticized the people for supporting them, Rio and Miles agreed that Super Heroes were cool.
When Venom attacked the hospital where Rio worked, she rushed her patients to safety, hiding them in a room from the violence. Spider-Man arrived and began defending the patients and staff as well. When things looked dire for Spider-Man, Rio shot at the symbiote assailant with a handgun, distracting it only slightly. He swallowed Spider-Man and she pleaded with Venom to release her son. Miles broke free and the cops, who had arrived on the scene, began shooting at Venom. Miles grabbed his mom to get her to safety but it was too late, she had been mortally wounded in the crossfire. Before she died in Miles’ arms, she lauded him for what he could do and whispered to him to never let his father know about his life as Spider-Man.
Rio’s reality was later destroyed due to an incursion of her world and Earth-616. But Miles survived on a patchwork planet called Battleworld run by Victor von Doom, AKA Doctor Doom. There, he offered a hamburger to Owen Reece, AKA Molecule Man. Reece restored the Multiverse and as thanks to Miles for his generosity, he restored her family, including Rio, on Earth-616. Though, she had no memory of her son’s alter ego. Jefferson, however, knew about his son’s after school activities. She found formulas for web fluid jotted on a piece of paper at home and an unmarked phone in her husband’s possessions. She confronted Miles and Jefferson, and being caught by her questioning, Miles told his mother that he was Spider-Man. Hurt that they kept the truth from her, she left them both frustrated, and struggled with the truth.
Eventually, Rio comes to terms with her son as Spider-Man. Rio and Jefferson then have their second child, a daughter they name Billie Morales.