Hi, Tara!
Most of my students are older, but I do have a fifth year Ravenclaw named Kit, who she might be able to interact with. Especially in classes, if you jump in there. (For reference, you're more than welcome to pretend your character was there the whole time. Unless you want them to be late, in which case, that's totally fine, too!)
Kit was essentially held back a year because of health reasons, and she's getting sick again. So if she and Melody were friends, perhaps Melody would try and convince Kit to go to the hospital ward or something? Or, if interacting in classes is easier, Kit doesn't have a partner in the Transfiguration class I don't think. So she could pop in there and we could see what they're like!
I also have two professors who she is more than welcome to interact with. Keiran is the Deupty Headmaster, and his wife is a professor/Head of Gryffindor. So if she got into some trouble, he would probably be around. On the other hand, I've got Declan who's basically filling in even though he doesn't have the right experience to teach his class. I think some of the students would probably have crushes on him, if she's the type. If not, it would also be funny for someone to ask him for tutoring and then watch how badly he messes up.