Wagering On The Wallflower (Young Victorian Ladies, Book 1) by Eva Shepherd
A wallflower
And an elegant gentleman...
Gauche Hazel Springfeld is reconciled to being left on the shelf. At a society ball, she is improbably asked to dance by charismatic Mr Lucas Darkwood. When she discovers it was all for a wager - he'll win a prize if he can turn her into marriage material - Hazel plans to get her own back! She'll frighten Lucas into thinking she really does expect that proposal - from him!