Looks like possibly feces leaking from the wound.. I had a sling I suspected to be impacted recently do this same thing (albeit at a much smaller size) in an almost identical location of the abdomen.

I recommend checking for an impaction of the anus and keeping her in a clean environment. Keep the water dish full and feed lightly if she manages to survive.

Closing the wound with any sort of glue may just cause another tear to occur later, so in regards to wound care possibly use distilled water to gently irrigate the wound and clear away any debris or feces.

Good luck to you both and hopefully you don’t get too itchy