Jenny Prezzioso is thought as a brat by the BSC members, except for Mary Anne, who actually likes her. In book 5, when Mrs. Prezzioso needed a sitter, everyone else made up excuses so they cannot sit for her. In book 4, Jenny had a fever and was sent to hospital.
She is called "Angel" by her mother. Mrs. Prezzioso dresses her up neatly. In book 7, where they putted on a play group, Jenny refused to put on a smock. It was Andrew, saying that he was a monster, made her wear a smock.
In the Summer Before, in Kristy Day's Parade, it was said that Jenny loudly declared that Kristy was her favorite sitter.
She is friends with one of the Pike girls, Claire, Margo or Vanessa.