I have a couple of recommendations, two post-apocalyptic novels by Diana Peterfreund:
For Darkness Shows the Stars - In a dystopian future, a genetic experiment has devastated humanity, and in the aftermath a new class system placed the anti-technology Luddites in absolute power over vast estates and the genetically damaged Reduced population. Elliot North is a dutiful Luddite who runs her father's estate, and when the boy she loved, a servant named Kai, asked her to run away with him four years ago, she refused. Now, Kai is back, and Elliot longs for a second chance with her first love, even though she knows it could mean betraying everything she's been raised to believe is right.
Across the Star-Swept Sea - Expands on the universe from the first. Centuries after war nearly destroyed civilization, the two islands of New Pacifica stand alone, a paradise where even the Reduction - the devastating brain disorder that sparked the wars - is a distant memory. Yet, on the isle of Galatea, uprising against the ruling aristocrats has turned deadly, and the revolutionaries' weapon is a drug that damages their enemies' brains, and the only hope is rescue by the mysterious spy known as the Wild Poppy. On the neighboring island of Albion, no one suspects that the Wild Poppy is famously frivolous aristocrat, Persis Blake, who uses her shallow, socialite trappings to hide her true purpose.
Both recommendation have strong, vibrant heroine leads, well-written romances and beautiful narrative, and raise intriguing questions about humanity and the price of progress.