Brace Jackson

"'if you’re anything like me at your age, getting talked into a night out by less studious friends and waking up shirtless the next day with more pain in my head than memories, on the couch of Brace Jackson. That was an awkward New Year’s Day. Even more so when Brace’s boyfriend turned up... followed by her other two boyfriends.'""-- Joseph Carrion, describing what people Charlotte's age do at Christmas in his experience. (Book 4, Sent Into Mediochre-Drive)"Brace Jackson was a friend of Joseph's at university.

Traits
When Brace and Joseph were Charlotte's age, she was one of his "less studious friends" who talked him into attending wild parties. On at least one occasion she let him sleep on her couch, although this made things awkward when her boyfriends discovered him.

It is unknown whether Brace was openly polyamorous, or whether her three boyfriends were unaware of each other at the time.

Brace is implied to have matured somewhat since then, as Joseph mentions that she would kill him if he let Charlotte follow their youthful example.

Sent Into Mediochre-Drive
According to an anecdote Joseph relates to Charlotte about his experiences of being her age, there was at least one festive season when she and some of their other non-studious friends convinced Joseph to attend a night out which resulted in him awakening badly hungover and shirtless on Brace Jackson's couch the following day. Things became awkward when three different boyfriends of Brace showed up in rapid succession and discovered him.

Joseph subsequently advises Charlotte not to imitate him in this regard, since her parents would likely murder him for it and - he notes as an afterthought - so would Brace.