It turns out that things are really bad with Sheridan. She's lost weight in the 20 days inbetween visits to the vets from 1.3 pounds to 1.2 pounds. She's also dehydrated and malnourished even though I watched her eat and drink in the last 24 hours.
Long story short is that due to the distemper the kittens had about 3 weeks ago, Doc T thinks that Sheridan has Cerebellar Hypoplasia now.
Cerebellar Hypoplasia is a defect in the brain of young kittens that results in a loss of fine-motor coordination. Affected kittens have trouble walking and maintaining their balance. It is cause by infection of the kittens with feline distemper virus short after birth, or infection while the kittens are in the mother's uterus.
There is no known cure for cerebellar hypoplasia.
That's basically it. It's really unusual for a three month old kitten to get it but Doc T's best guess at this point is that this is what is wrong. They are keeping Sheridan at least overnight to watch her eat and drink. They want to see if she still has a survival instinct since the loss of balance often messes with a cat's appetite.
Doc T tells me that these 'herky-jerky' cats, while permanently disabled, still make good house pets. They are not in pain and are amusing if you like watching cats who look like they've just had a few highballs. However, it is up to Furry Friends Rescue to decide if Sheridan has any chance of being adopted and up to them if they will allow Sheridan to live. If she doesn't have a survival instinct or FFR decides that in this glut market many kittens, she won't be adopted due to her disability, there is a good chance that I will not see Sheridan again.
Sinclair, on the other hand, is two pounds now. I need to email the guy who wanted Sinclair and Sheridan and explain the situation and hope he will accept Delenn and Sinclair. I think he will. Both kittens are in fine health and have bonded to one another. Also, I don't think he's going to want a permanently disabled kitten.
My first instinct is to adopt Sheridan myself if she still has survival instinct, but I have to really think about it. Do I really want a 'herky-jerky' cat? I don't know. But I don't think I can condemn Sheridan if she is allowed to live. I can deal with the issues. After all, Alex and Johanna have Tigger.