My smallest lamb, Venus is tiny compared to the others.
She was a hung lamb and didn't get colostrum down her in time (mum's milk didn't come in properly for nearly a week she had such a rough time

)
I am sure the only reason she survived is because one of my goats kidded the same day and let her latch on and get goat colostrum.
She has always been smaller, and is the first to get squitty. She is also the only sheep of mine ever to get strike
However, she seems to have turned a corner... I am hoping that she will catch up next spring!