Philosopher's Stone

Susan Bones is placed in Hufflepuff house by the Sorting Hat.

Order of the Phoenix

Susan Bones is one of the students who attend the first meeting of the group that will become Dumbledore's Army. At the meeting, she asks Harry if he is, in fact, able to produce a "corporeal Patronus." The phrasing is familiar to Harry, who asks if she is related to Amelia Bones. Susan confirms that Madam Bones is her aunt.

With the escape of the Death Eaters from Azkaban, people are once again frightened that Voldemort may be returning, despite the official Ministry reassurances. Susan Bones, who had lost several cousins, an uncle, and an aunt, to the Death Eaters in the previous round, becomes something of a center of attention in the school. At one point, she asks Harry how he stands the fame.

Susan is also one of the six members of Dumbledore's Army who see Draco Malfoy attempting to jinx Harry on the Hogwarts Express, and promptly return fire, leaving Draco, Crabbe, and Goyle looking like gigantic slugs squeezed into Hogwarts robes.

Half-Blood Prince

Susan's aunt, Amelia Bones, is murdered, probably directly by Voldemort.

Susan later appears during apparition instruction, during which she splinches her leg off. Adult wizards are on hand to reattach it, of course.

Deathly Hallows

While Susan's name is not mentioned, we know that Neville had summoned Dumbledore's Army to assist in Harry's mission. So we assume that as Harry, Ron and Hermione return to Hogwarts to seek for Rowena Ravenclaw's lost diadem, she either is in the Room of Requirement with other Dumbledore's Army members, or else arrives later with the members of the Order of the Phoenix. We believe she was also present for the final Battle of Hogwarts.