The Weaver Bride by Lydia Gregovic

Lovett is a silkwitch with less than 3 years left to find a Weaver husband so she isn’t forced into the cloister never to be seen again. In order to increase her odds she makes a deal with Elliot. She gets entrance into the Vainglory competition with a prize of marrying one of the most eligible Weaver bachelors. In exchange, Lovett has to uncover the cause of death for the previous Vainglory winner, Ophelia, who happens to be Elliot’s sister.