My baby also around one week old, 3.2kg also give her breast feed but not work. As i have sore nipples already so just let her try around 15mins each side and then give her milk powder, she also need nearly 3oz ar.
My bb now 18 days, weighted 3.49kg when he was born. Now eat 100 ml (~3.5 oz) mixed with formula and my milk coz he does not know how to suck properly and made my nipples hurt. So i have to pump the milk out for him.