Hello Xenia !
After a sick kitty has access to food again it take a 7 days of recovering before they are not under a blanket anymore also if they are no longer hungry :-)
How much time there will be left before they are recovered you can see when you click your kitty's info button you will see a line about the "Health Recovery".
Should you don't like to wait for what ever reason or your breeding plans with that kitty you can also obtain the "Healthy Cat Vitamin Bottle" which cures you kitty instantly.
If you think the kitty is longer in recovery than it should I'd file a ticket with the kitty's ID for KittyCatS! to investigate that.
I hope this helped :-)
P.s. I see you posted a pedigree link to your kitty but we can't access that link for other's cats in that sense your kitty's data is private for you only.
Unless you activated a pedigree link in world we can acces data about your kitty by clicking it in world.
This can be done via the check box on it's pedigree page at the very top right.
Script error? Food, illness...
