Soula, one of the crit group members, pointed out that it's unclear that the knight and berserker are the same. So, revise to this:
Sixteen-year-old Chloe felt no shame about sitting in the middle of the street, crying. Wouldn’t anyone who was plopped naked into a world where monsters are real and indoor plumbing isn’t? The Red Thread, a 70,000 word YA Fantasy for teen girls, shows what happens to Chloe when she's jerked abruptly out of her modern New York life and into a world where she must challenge all she used to believe in. On her search to save a brother who doesn’t want to be saved, Chloe meets with a knight who tends to go mad with bloodlust at the most inconvenient times. She finds herself falling in love with him, but he's more focused on saving a kidnapped princess. In the end, Chloe discovers that in order to have the life she wants, she must learn to accept the knight for who he is, and to do all she can to change her brother.
I believe you'd like The Red Thread because of your work with _____. The Red Thread is funny and entertaining, but there is a serious undertone that would appeal to modern teens: a connection is made between Chloe's brother's magic use in the new world and his drug use in his old one.