They are all sweet when they are a few weeks old - it's only later that the trouble begins 
Crocs, a warm dressing gown and a torch - for night time toilet trips.
More kitchen roll than you think plus an enzyme cleaner for accidents.
A lead and collar to get her used to them in the house.
Someway to keep her secure and in one place in the house - crate, pen, baby gates.
A copy of Pippa Mattinson's 'The Happy Puppy Handbook'
A soft brush to get her used to being groomed while she is little.
Food - the same as she is on now, even if you plan to change her food later.
Somewhere for her to sleep - 2 or 3 vet beds are ideal as they wash so easily and you can switch them out quickly if she messes.
A camera at the ready at all times. They grow so quickly that within a month your little puppy won't be so little at all so you want to take tonnes of photos and video while she is small.