Note: The cut-off bubble on the last page isn't a mistake, check the raw. Seems an artistic choice by the mangaka, so I rolled with it and put my closest approximation of what was probably in there.
Thank you so much for the group yuri doujin; this sort of thing is rare, at least where no men are involved.
As an aside, have you ever heard of ECT? It is a tool that losslessly optimizes, among other things, jpeg and png files (using modified versions of jpegtran and zopflipng.) I was able to reduce the file size of your release by 4%, which isn't much, but given the size of the pages, is still about 6 MB (going by the unzipped pages, the difference is a fair bit more.)
If you're in Windows, the dev provides a pre-built exe. Still not sure if you'd want to do it, and don't want to overly complicate your release process, but ECT is actually pretty easy to use if it matters.