His mum and dad's weights are exactly what Twinkle's were.....she was also the largest in the litter. I always thought she was quite skinny, even when she was about 7/8lb...she filled out a bit from 10 months (ish) but the vet says she isn't overweight...she actually looks a bit better because she's not so 'gangly' now
The silver on Derby's head will change from silver to tan...not too sure at what age, I think it depends on the individual yorkie. Twinkle was silver and tan by 8 months with no black at all, but Wicket, who is almost 9 months, still has lots of black on his back, silver on his head and legs and a tan face xxx