Hey there, Eve, welcome!

I haaaaave:

Fleur Rey is King Lukeson's cousin!  She's an incoming second year Hufflepuff.  She and King's sister Sybille are very, very close, and they're always baking.  She's very sweet and a forever optimist.

Clementine Rookwood is an incoming sixth year Hufflepuff.  She is the mothering sort who would likely take a younger student under her wing or stand up for them.  She is in King's house and year!  She is likely very friendly towards King and concerned about him.

I also have a few other Hogwarts people.  I'm not sure who would be best for your characters.  My second years might be good potential friends, though, depending on where Idris ends up being sorted. 

Archer Belby is an incoming second year Ravenclaw.  He is somewhat of a walking disaster.  The poor boy is timid to the point of panic, even though he is very intelligent and incredibly sweet.  He has been the victim of a few pranks, and he tends to clam up when he's put on the spot.  He is incredibly interested in werewolves, ghosts, vampires, etc., and he would love to meet people who also enjoy those subjects.  He would be a very loyal friend to someone who gave him the chance.

Thomas Montgomery is an incoming fifth year Ravenclaw.  He's a keeper on his house quidditch team.  He's a transfiguration enthusiast with a short temper.  His mother ran away with a pornographer, and it haunts him.