I haven't found anymore that focuses on the batfamily although I do know the author has made more as bakaupdates shows: https://www.mangaupdates.com/authors.html?id=2485
but she's written/drawn some other couples like superbat or dickroy that are online
https://myreadingmanga.info/gd-mechano-the-outsiders-dj-between-bathroom-and-bedroom-eng/
https://myreadingmanga.info/izumi-yakumo-babhel-justice-league-dj-eng/
https://myreadingmanga.info/gd-mechano-the-outsiders-dj-kuchibashi-ni-cherry-eng/
there should be one more superbat one that she's done on that site too
(I know how you feel, I'm very much in love with this author's works as well and haven't been able to find out where I could buy some physical copies. I really want to support her work, so I feel bad that it's online, but I have no idea how else to get it. : Though bakaupdates does have her twitter I think and her website on there, it's all in Japanese, so there is that.)
Good luck with that!
And if you're into fanfictions, there are some really decent ones about the batfam.
I would like to read more from this mangaka but I can't find any. If anybody can find any please link it to me!