Welcome to Yorkie Talk. At 5 weeks, it is hard to say how they will mature in terms of personality, looks, coat and size. Smaller at birth doesn't always mean smaller as an adult. Smaller does not mean sickly either.
Sorry, I am of no help. Go with your heart, and make sure the breeder is offering a great health guarantee.
Best wishes!
__________________ Kristin, Max and Teddy  |