Sarah Grey had Nik at nineteen with a man she only knew by Michael. They met on Sarah's first mission and dated for only a few weeks, but Sarah was very much in love with him. Her feelings lingered for years, even after he pretty much disappeared.
Nik was the center of Sarah's world. Sarah took as much maternity leave as she could and she stayed on desk duty until Nik was two because she didn't feel comfortable leaving her with anyone overnight until then. She eased slowly back into field missions and let her sister babysit Nik while she was away.
Nik was a little troublemaker, always into everything and trying to explore in places she shouldn't. She had a habit of getting on top of things: counters, dressers, the fridge...not the safest places for a toddler, but she liked to be up high. Her mother taught her to fly on a broom as soon as she felt it was safe, and her love for heights translated well into her love for quidditch later on.
Nik's first sign of magic came rather violently when one of her teachers turned out to be a bit of a predator. He got much too close and Nik started panicking and...then he was bleeding out on the floor. Like you do. Not the best experience for a young child to have, and it definitely left its mark on her psyche.
Nik went to a private muggle school after that incident, one that had good reviews from several of Sarah's coworkers. There she met and became close friends with Tori Summers. Sarah made a point to befriend Tori's parents once she saw how close the two girls were, and began trusting them with her daughter when she went on her "business trips." Nik did well in muggle school, enjoying science and PE more than anything.
Sarah had always been a bit too fond of alcohol, but it didn't become a true issue until she found out Michael was dead when Nik was eleven. She'd been holding out hope that he would come back for eleven years, and the finality of the news very nearly broke her. She did her best to hide it from Nik , but she was perceptive even at that young age and she knew something was wrong. She found her mother dead drunk on the couch one evening and, after finding and disposing of all the liquor she could find, she made her mom promise to stop. Sarah, of course, promised--and she tried her hardest, she really did, and she got a bit better, but for the most part she just hid it better.
Nik went to Salem Witches' Institute like her mother, and like Tori as well. They stuck together there, and Nik quickly became known for breaking dress code and breaking noses. The stress of worrying about her mother on top of her natural hotheadedness made for a nasty combination that led to many, many detentions. She did well in her classes at Salem as well, excelling at DADA--and she proved her prowess in hallway duels. She was a member of the quidditch team all four years, as well as a member of the dueling club.
With her daughter away at school during most of the year, Sarah began going on longer missions, and would often not let Nik know she would be gone unless she would be missing a holiday. Sometimes Nik would go weeks without hearing from her, despite countless owls, and Nik worried the whole time. She didn't find out her mom's real job until she was thirteen. She was snooping in the attic and accidentally cut herself with one of Sarah's weapon gadgets, and she demanded to know why her mom had those things. Sarah couldn't keep her secret any longer.
After that incident, Nik was grounded for a good two weeks since she'd broken the don't go in the attic rule.
In her fourth year at Salem, Nik got into a bit too much trouble, and Sarah's old friend, the DADA teacher at Salem, managed to prevent her from being expelled, but she wasn't allowed to come back the next year. Sarah started making arrangements with her job to move to England--she was lucky she'd been offered a position at the England office, and they moved on short notice. Nik didn't even have time to say goodbye to Tori.
At Hogwarts, Nik was sorted into Gryffindor, and she wasn't happy about it. She wasn't happy about anything. She wasn't happy about leaving her old home. She wasn't happy about leaving her old friends. She definitely wasn't happy about leaving her best friend. Sure, she understood it was kind of her own fault, but in her defense a lot of people had turned into assholes over the summer and she wasn't about to take shit from them.
Soon into Nik 's fifth year, Sarah got picked for an undercover mission. Nik didn't want her to go, but she said she would be back before Nik even knew she was gone, and she promised she'd be safe, and she asked Nik not to owl her until she said it was okay again. Before Nik knew it, the time Sarah was supposed to be back came and went, and her grades went down, and her temper got shorter. She drove the muggle studies car into a tree. She started picking fights. She hurt another student really bad on accident. She very nearly stepped off the Astronomy tower.
It wasn't good.
But then her mom came home, finally, after a good bit of trial and error to get there. Nik was over the moon, but she was also amazingly pissed off. It took a lot of talking and a good bit of time, but they worked through it. Sarah quit the CIA and became an auror, which, while still dangerous, kept her much closer to home.
Nik played quidditch at Hogwarts as well, and enjoyed it as much as ever. She came to really look up to her head of house, Sarah Norman, despite all the detentions she gave her.
Sarah got married to Mathew Starnes, who Nik gave a bit of a hard time but eventually warmed up to. They adopted Kinzie, who was as much if not more of a troublemaker than Nik , and a bit later had a baby boy named Justin.
Tori came to Hogwarts in her seventh year, and she and Nik got caught up. Tori became a healer after Hogwarts, and Nik did a bit of this and that for a while, then became a Holding Cells Guard, and eventually Supervisor. They got married soon after they graduated. A few years into it they adopted Nymeria, who was closer to Nik than to Tori but she still loved and was loved by them both.
Mathew and Sarah got divorced a few years later. Kinzie was killed by a vampire who is lucky Nik never got her hands on them. And Justin--little Justin died of Scrofungulus during the epidemic. Both their deaths hit Nik very hard, but they hit Sarah even harder. Trying to take care of Sarah helped Nik ignore her own greif, and she has yet to really address it.
Tori had a bit of a mental breakdown and spent a good chunk of time in the psych ward at St. Mungo's, barely talking to Nik at all, and when she finally felt herself enough to leave, she divorced Nik and they haven't spoken since. There were no hard feelings really--Tori just didn't want to use Nik as a crutch, and she didn't want Nik using her as a crutch either. Nik hated her for a bit, especially when her PTSD got worse, but she got over it. Sort of. She contemplated therapy--she's progressed enough to know she needs it, but she's not quite ready to open up to anyone so much again.
Nik was overjoyed when she finally got into the Aurors--it took ages because of administrative errors and, partially, her own idiocy, but the Head Auror at the time, Renee Delacroix, was nice enough to give her a second chance. She enjoys her job a lot, and she's trying to get into the Hit Wizards.