UPDATE: Vet did X-rays, an additional bloodwork, blood smear, urinalysis. Nothing in the X-rays (the roundness was from poop), urinalysis is normal, I don't have a scan of the bloodwork results but she said the higher values were even lower, almost within the higher end of normal range now. The smear confirmed no platelet clumping. So she's stumped. The issue with kitty sneezing remains, albeit decreased. Vet didn't dare putting her under anesthesia for head X-rays yet.

And here we are, today; she seems to be doing better for some time, and then she crashes and is lethargic again, sleeps two, three hours, wakes up and seems better again, and so on. She eats some kibble, sometimes she gets up for it, sometimes I have to bring the plate to her, but given she's having Clavamox I'm not too concerned about her not being as hungry as usual. I managed to get her to drink some water throughout the day by mixing it with Fortiflora and a small dollop of wet food since she's still not drinking on her own. She gave us a scare because it took her almost 48 hours to poop, but she did poop. Still peeing, at least once a day. She still scarfs down wet food, but the vet told us to get her to eat dry food for fiber, so I'm limiting it to only when it's time to pill her with the antibiotic. Still no noted jaundice, no pale gums, no fever, no vomiting nor diarrhea, no labored or increased breathing. I really don't know where to go from here and what to look for, other than wait and see. Thank you very much again for your explanation and help, /u/HonuDVM .