Thing is, Petunia had Muggle parents, so if she was magical she would have been Muggle-born. A squib is a pure-blood who can't do magic. That said, I love the idea of Petunia having magic but unwilling to own up to it! This should have been in the film
Hugo was always pestered by the pretty Lyla Hawkins, who came from the Pedro family. The Pedri family, her moms side, was known for beating the crap out of the people they loved- and Hugo would never hit a girl. Nobody understood but his parents.