The girl pulls the bow across the strings and makes music -- anxiety-relieving music -- before she goes in for another session of treatment that has already cost her an ovary.
"It makes her forget everything," says her 43-year-old mother Lourdes, who brings Victoria to a children's hospital in Caracas every two weeks from their home in Los Teques in the northern state of Miranda.
The music lessons are a treat from an award-winning music program called the National System of Children's and Youth Orchestras. In Venezuela, people just call it "El Sistema."
It has been around for decades, working to rescue children from poverty and street crime through music education.
And in recent years it has expanded into hospitals, detention centers, shelters and remote settlements for indigenous people.
In downtown Caracas, the state-run Hospital JM de los Rios is the first to go musical with El Sistema.
Children receive classes while they are hospitalized or undergoing chemotherapy. They attend concerts or are lent instruments to play during their long periods of convalescence.
"Children learn very fast, especially those that are hospitalized, because they are here all day and have nothing else to do: they can just pass the time or they can learn something," said Marlon Franco, a musician and driving force behind the program.
Victoria's face is pallid. She wears a colorful cap to hide her hair loss. She giggles as she plays the violin, and is part of a quartet with other kids who play the maracas, the mandolin and a 'cuatro,' a Venezuelan stringed instrument for playing folk music.
"I also want to learn to sing," Victoria tells one of her teachers.
Music for cheering up and enduring
"Music and all arts in general help the child have a much more positive outlook. It helps them relax and more readily accept treatment against leukemia, for instance," said Susana Pachano, a doctor who heads the hematology department.
Near her, children in bed with cancer-fighting chemicals dripping into their veins listen to a waltz played with a violin, maracas and a double bass.
"It cheers up the unpleasantness of the chemotherapy, the transfusions. It helps the children and their families," Pachano adds.
In the waiting room, a young orchestra director who came out of El Sistema, Dietrich Paredes, chats encouragingly with two kids who are about to strum 'cuatros' with other musicians.
"Keep fighting. We are proud of you," he tells them. Then the music starts: two mandolins, some maracas, a violin and a double bass. Parents and relatives look on, their faces a mix of hope and sadness.
Yaczuly Echeverria, a 23-year-old philosophy student and violin teacher at the hospital, says the kids are not treated with pity but "rather as human beings who are growing and right now are going through a very rough time."
Echeverria likes her work but of course at times it is challenging.
"It saddens us when they get worse, when they die," she said.
"We try to encourage them and the parents and give them hope. We try to make the time we spend with them happy, regardless of what happens later."