The Innocent by V. K. Ludwig

When your test subject turns you into the experiment, the loss of control is imminent.
Max discovered a terrible complication, pushing the government and their control over human procreation to the edge of collapse. As a scientist, it’s his job to find a solution, but test subjects are hard to come by. Until a fiery clanswoman arrives at the Districts, who is none other than Autumn, the sister of the chieftain of The Clan of the Woodlands.
Things go great until they go all wrong because Autumn is desperately trying to find something. Besides, numbers and charts have always bored Autumn – she prefers to be hands on. Beautiful and hot-headed, she makes Max question everything he stands for, and shakes the Districts to its core.
How can you control your experiment, when the test subject refuses to play by your rules?