Mor is a 29 year old librarian with a blood curse and an Unbreakable Vow. Her ex-fiancé is Brooks Watson, and she left him at the altar in 1889. Whoops! She's also American, and was born in Chicago, but they moved to Britain in 1873 and she was a Slytherin who finished school in '83.
Interpersonally: Mor comes across as aloof and occasionally rather maudlin; she does not make a strong effort to be friendly. She is very loyal once she is friends with someone, and is most likely to be friends with people who have strong academic interests and/or come to the library consistently — she is very curious about what makes people tick, so is also interested in people who buck societal trends or, conversely, who excel in society. She historically has been very interested in curses, dark magic, and shipping history, so folks who are interested in those (or are cursebreakers) will also be a hit. Anyone who spends time with Brooks is also of interest to her, including Unspeakables. She is also interested in people who spend time with her toxic bestie Drusilla Pettigrew.
Mor can also be medium-chaotic — arriving late to parties or leaving early, experimenting with potions or substances, and being much more interested in offbeat events than she is in traditional balls. Also flirty, particularly with people she finds to be of interest? I think she is currently a virgin, but she has certainly done other things, and while she's in love with Brooks she probably tries to forget that on occasion
Mor is good for academics, people who like shipping, library guests, poking at what makes your character tick, dark magic, and trying to stave off her sense of impending doom by any means necessary.
OH ALSO, she has a British stepmother (married her dad in '73) who could be YOUR sister or cousin! Also plz play Brooks connections so she can be super cool & normal to you.