OK so I have a few that would likely have met nicole

Shinobu Yukimura- so he's the mabeob potions professor however he went to hogwarts during his school year. He was a slytherin but at the same time he was one of the more tolerable slytherins. they would have gone to hogwarts at the same time and were likely class mates. While he did pretty good in most of his classes Potions was by far his strong point. Granted I'm not sure why they couldn't have been friends or at least gotten along while they were in school.

Seok Kim- so he's a Griffindor and excels in Charms (It's honestly his favorite of all of his classes.) So I'm thinking Seok would often come to her for help on the very few things in charms he doesn't understand. Honestly I think she would likely be his favorite of all of his teachers. So I'm sure there will definitely be a lot of interaction between them.

Katsu Greyback- So while he's no longer a hogwarts student having moved on to aridorn he was a slytherin a couple years prior. He excelled at all of his classes spending most of his school years in the library. So I'm thinking there is a good chance she saw him around quit often he's the kind of guy that would have asked for her opinion on any homework he owed her. granted I believe she would have been starting her fist year of teacher when he was starting his last year of hogwarts.

Amable Yamamoto- so this one's my half french half Japanese character. He's a former Beaubaxtons student and is now their DADA teacher. there is a chance that they could have run into each other at one point other than that I've got nothing but if you can think of anything else here he is.

Mkay I'm gonna throw some bbies at you and see if we can figure some stuff out. Sorry I'm not the best with plots D:

First this is Zerro he is the flying prof over at Beauxbattons and they are the same age. In general he is a pretty laid back person who just wants people to be happy. He lives in France and grew up between there and Greece.They could have met when she went traveling after school or during a triwizard back when they were both in school? Zerro is in a relationship with the Centaur headmaster of Beauxbattons, as much as he appositely loves it he knows that others might not take so kindly to the idea.

Next there is sydney schyler schield. He is the same age as Nicole as well and they would have both been in Hogwarts together. He was a Ravenclaw, but his older brother was a Gryffindor so he would have been around there sometimes. Anyway. Sydney is kind of the strong silent type. He isn't the best at expressing himself, and never was. Not until he really got into music. There he found an outlet for his feelings. After Hogwarts he moved to America where he formed his band and met his first wife. Sometimes around baby one he started to make it big with the band. Now he has two children and a divorce but the band is doing okay. now he is in the beginnings of a new relationship with a younger musician. Maybe they were friends or something in school and kept in touch? I dunno

felix lincoln satagori-hedlund is a teacher at Salem, he went to Durmstrang and is Swedish. They would have meet at a Triwizard or possibly while she was traveling. He traveled around most of Europe before getting his job at Salem. Either way Felix was (and mostly still is ) and awkward turtle. He doesn't do that well with meeting people and it takes a fairly patient person to get to know him. Unless they get lucky. Felix has little concern about others feelings really. He quickly get's bored with conversations and just generally is bad at being relate able. But if she gets past that he is a pretty good guy, sometimes a little too excitable about the things he actually likes but he tries to be a good friend.

I also have a couple vampires wondering around Europe
dekker andrew vaughn who owns a tattoo shop in London. He was made just after the second world war where he served in both theaters and lost his leg. And niklaus luka alvang who co owns a bar just outside of London with his girlfriend who he recently turned. Nik is from the Ukraine and a fairly y new vampire himself only getting turned 17 years ago.

There are also a couple students who happen to be Gryffindors kasper theodore wilkes and hugo oliver weasley.

And I have more charries floating around but these are the ones i figure she would/ could know pretty easily.