Well I have a ton of characters you could choose from. I'll just list the ones that are about the right age, though.
Students:
Nessarose Wood - she's a Slytherin, going into her 6th year in the fall. She was adopted so it's not certain if she's Pureblood or not. People just assume it because most folks don't know that she is adopted. She doesn't tell anyone because her parents didn't want her to say. It's a bit of a long story, but if I need to explain it I can. She's kind of on a revenge path right now, but most of her being mean is just when she's sarcastic.
Trisha Ivanov - going into her 6th year in the fall, Tris is a Ravenclaw and comes from a family of Muggles that are ghost hunters. She wants to work with Spirits and Beings when she graduates. She's always been the outcast, but has a group of friends she hangs out with now. But she is always open to knew friends, too.
Adrienne Poliakoff- she should have graduated, but she left Hogwarts at Christmas and is still waiting on being able to take her NEWTs. She may just take them outside of Hogwarts and move on to University. Either way, she's a Ravenclaw and technically still a 7th year. She's got a temper, but generally tries to avoid hurting anyone.
Christian Zabini - 17, one of the two Zabini twins. His brother, Apollo, is an NPC right now. Christian is a Hufflepuff, which is strange because his father and brother and mum were/are all Slytherins. It's because he feels like he needs someone's approval when he doesn't get it from his father. Apollo is the heir, so Christian is kind of pushed to the side a bit. He also has a very serious sense of justice.
Adults around Chocola's age:
Keiran Hayes - 26. Ex-Transfiguration Professor, now writes textbooks, and is in charge of a secret project against the Ministry, which will help protect half-breeds. Married to Melissa (Millie) Hayes, and expecting twins like, really soon. So he's a little stressed, but his Slytherin background means that it doesn't always come out the right way.
Audriana Swan - 25, ex-Gryffindor. She doesn't need money because of what her Grandmother left her, but she works anyway. Her job isn't exactly well known, because only someone who knows about the job can tell someone else about it. So, for example, if my character Keiran asked Audriana to find something or someone for him, he could then tell Avery about her, and Avery could ask Audriana for help. Basically, Audriana finds people and/or things that are missing or stolen or don't want to be found. This includes having run-ins with Death Eaters and sometimes some stealing.
Avery Ivanov - 25, Ex-Durmstrang student. Only related to Trisha through marriage, as they both married into the family through Robin and his brother Caspian. Avery works with Dragons at the Ministry, and is helping Keiran with his project. She's acting like the eyes and ears of the team, keeping a lookout for anyone that might want to go after the half-breeds staying with him. She's often really open about her emotions, but if she's afraid of being rejected in any way, she never mentions her problems.
Holland Fox - 25, Ex-Ravenclaw, works at a Muggle hospital. She pretty much always wants to be right, but doesn't actually mind being corrected most times, since it helps her learn. She's the head of her department at work, and is very observant. Right now she doesn't have a whole lot going on.
Bentley Pierson - 23, ex-Slytherin. Heir to a company, he works with his adoptive father at a large company that takes bad or failing companies and finds them new marketing/advertising plans to get them going again, as well as providing money for them to build their business. Ben works with Death Eaters to some extent, though he's going to actually join up very soon.
by 
.gif)
If you need her for anything else then she's here! 
