Hi again all,
I found this link and had originally included it with my last post in this community, but learned afterwards that the blog owner didn't want people to link to their translations so I removed it. I have since asked for and received permission to post it here, so here you go.
Maybe some fans knew this already, but this was new to me: After this original 18 light novels were published, there was a mini-series consisting of 2 light novels released in Japan. The series is titled "Saiunkoku Monogatari Secret Scrolls: Ask My Bones", and it details events which happen AFTER the ending of the original light novels.
Needless to say, if you don't want to know the final ending to the series, don't click the link. After reading volume 2 I personally can't see anything else being released for SaiMono unless it's a spin-off, but that's just my opinion.
Credit for the translation goes to tumblr user theyseemewhalin.
(The link also has translations for volumes 2 and 13 of the original light novels.)