How do I backup, or save to external sd, or export bookmarks on Firefox 47.0 for Android?

I have been using Firefox 47.0 for Android on a BLU Studio One + for way too long, because I already had a very extensive list of bookmarks I want to keep (ideally with full data including creation time etc.) by the time I found out there was no backup or export available. My phone is not rooted, and I can find no sly method to grab the database (presumably a db or sqlite file in my profile?) with adb, assuming that that file would then be readable or usable to restore or force import... The data is there, it can be read by the browser, so it should be exportable. There used to be addons that would export bookmarks, but I can find nothing that can be installed on 47.0 Sync is not an acceptable option, unless I can sync it to my local machine with out the data ever leaving my local network. I.e. NO external Firefox account or server involved! How? Possibilities?