The book blurb is quite misleading - the story doesn't really center around the two sisters so much as it does around a political intrigue. The main povs are Taudde, a foreign sorceror, Leilis, a woman working in the flower house, and Nemienne, studying sorcery.
I enjoyed the lovely prose and the intricate worldbuilding. However, I didn't really feel emotionally engaged. The novel didn't really explore the character's feelings much or even the romances. So while I enjoyed the book enough to finish it quickly, I can't say that it made me feel anything in particular.