First, diapers are not wet. You don't have to buy NB (minimum size), you can buy a slightly larger size S or M, and you can use it when you grow up. NB size: If your sister receives too many diapers, I'm afraid she can't use them all.

Baby sleeping bag: If your sister is not ready.

If your sister is more particular, it is not recommended to buy milk powder bottles and the like. Newborn babies don't need milk powder if they have enough breast milk. Moreover, too small baby milk powder should not be changed to different brands, which will affect the stomach. As for the bottle, some babies will choose pacifiers, and buying a bottle may not come in handy.

Toys:

Music bed bell and music fitness rack are recommended.

It is recommended to buy something with bright colors but soft music or adjustable volume, which is good for your baby's vision/hearing.