Hey there, Steph!

I have 3 Hogwarts characters.
Unfortunately, none are in her year, but I have two in her house that she might either know or meet eventually. I'll list them in order of usefulness.

Thomas Montgomery is a Ravenclaw Fifth Year who is obsessed and very talented at Transfiguration. He also plays as keeper on the house quidditch team. He can be fairly reserved, except among friends. In his first year, it came out that his mother ran off with a pornographer, so Ada likely heard of that scandal. He's a very nice boy despite being touchy and prudish about the subject. He's a loyal friend and would at least make a good study partner.

Archer Belby is a Ravenclaw First Year. He is also painfully shy and awkward. He is very interest in magical beings (ie. Werewolves, ghosts, vampires, etc.), but he loves to read about anything really. He is especially antisocial because his mother works at Hogwarts as the astronomy professor.

Fleur Rey also exists. She is a Hufflepuff First Year, but, likely, she would just try to feed Ada random baked goods.