a few months ago, my little juvey male was terribly de tailed, she had nipped a few times, I seperated them to eat after that, it was okay.
One morning I went in to find blood everywhere, and he had atleast half his tail completely off.
Your girls tail will dye there, and probably fall off. I would keep her on paper towels, and off sand if thats what ya have, until its healed. Otherwise it can get really infected.
I used a cotton ball dipped in an iodine solution
(NOT not the stuff they used on us as kids that burned.)
This is benadine, or the generic one, Povidine solution, bought at any cvs or drugstore.
Then I put neosporin or triple antibiotic ointment on it several times a day until it healed. Thats why ya have to get her on paper or her tail being treated with ointment will pick up everything / sand.
And also seperate her now. Someone you have her with is a very aggressive eater and just grabbing aimlessly or a tail biter, keep an eye on everyone in that tank.
Hope she will be okay. Also if that tail is biten almost through like it appears I would , hold my breath and SNIP IT clean.
Let us know how she does!
Heres my little guy awhile after the attack.
Navajo male juvey C. nebrius DE-TAILED by mate.

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Eve / PHEve