The first two colums of Renko's last bubble probably mean something like "I'll let you look at it for a short while", but since I couldn't find a translation for what seems to be either "代見" or "代貝" I can't be sure so I left it untranslated.
I think it's probably 代見して. 貝 is the kanji for "shell."
Therein lies the problem though - one of these is fan art and the other one is, again, questioning if that's relevant to her current status, not some point in the past. This is still an assumption, not a guarantee that it's not a prosthetic as opposed to a brace to prevent her hand from touching the blade directly. The update is in a few hours - just be patient for any actual reveal on this. We can fix it if needbe based on real information instead of assuming.
It'snot just combat experience; IIRC when it comes time for a regiment to be reformed, either because it survived to the end of a Crusade (which, lol) or because it was so shattered that it needs to be reconstituted (far more likely), an honour guard consisting of the most decorated survivors are sent back to the homeworld with the regimental flag/banner. That Nightsider there seeing her family again isn't just a veteran survivor, girl is a friggin' surviving war hero. This girl could probably shake hands with Commissar Cain as an equal, not that he'd see it as such.
With that being said, and something that I always as a mandatory standard: shoutout to Nisakusa for those amazing drawings. Extremely kind and fun artist to talk with! They certainly deserves more recognition imho.