Series
There are 3 books in the The Chemical Garden Trilogy series.
In a dystopian future where genetic engineering has left humanity with catastrophically shortened lifespans, sixteen-year-old Rhine is kidnapped and forced into a polygamous marriage. A haunting exploration of mortality, autonomy, and the desperate measures taken to preserve the human race.
All 3 books total 1,095 pages.
The Books Oracle — track the series you are partway through, and see what to read next.