Hayley is a kind girl. She would always say hi to Tom and his friends whenever she saw them. In the High School Years series, Helen was constantly mentioned by Aunt Sally. She reveals that Helen was very fond of Tom as a child. She even named a doll after him. When she got older, she still kept the doll. In "The Final Frontier", Tom said hi to her as she was passing by, and coincidentally, he runs into her at Froyo World in the third movie. In the Forever Sophomores series, she is in Tom's Marine Science and Geometry Class.
Hayley has fair skin, brown eyes, and brown hair. Her outfits vary throughout the series, but she is mostly seen in one outfit, consisting of a purple t-shirt, blue jeans, and brown sandals. Sometimes, she would wear striped long-sleeved shirts, dresses, boots, or sneakers.