
I know the KC do accept late registrations of individual dogs and circumstances such as your own are very possibly the reason they have this rule. It is a more expensive way of doing things (from memory of a press release some time back, around £50+ per dog to use the facility).
I hope the little 'un goes from strength to strength and as said by Carrington, registrations are currently going through very quickly so you should be able to wait for some time yet before registering any of the litter :)
Fingers crossed for you, Teri