A Match for Melissa — Kathryn Kirkwood

Once Upon A Season...
...deep in the heart of the country, there lived a pretty young miss with raven tresses, who dreamed of a London debut. But alas, Melissa Harrington's future lays in the hands of her nipfarthing stepmother who thought only of matching up her own two daughters. Worse still, the lively, sweet-natured Melissa had to help the family by posing as servant to her stepsisters when they were launched upon the ton. And thus, it came about that the Harrington "maid" found herself behind the scenes at a society ball, snatching a moment from her menial duties, on a starlit balcony.
Suddenly, there appeared before her a handsome stranger with an eye for beauty and a passion for astronomy. One moment, Melissa was discussing with him the heavenly constellations, the next, she was in his arms for one enchanted waltz...and the next, she was in love. But later--when this nonpareil, the Duke of Oakwood, sought out his bewitching, half-glimpsed dance partner--fate was to lead him in a merry dance of mistaken identity, misplaced attentions, and a daring adventure in which only fate could determine the destiny of two hearts...