[cypher]

Basic care really is very much the same as syrians Ruby, as CMB said a sand bath is more of a must for dwarfs, they really do love it & it keeps their coats in good condition too, the other thing she might need to be aware of is that dwarf nails tend to grow a lot quicker & longer than syrian hams if not kept in check so some good safe rough surfaces in the cage (little terracotta flower pots are good) as well as the sand can help.
The 6.5" silent spinner is a good size for most dwarf hams but they really don't work well any more but there is a newer wheel at P@H (& Amazon I think) that looks very similar (can't remember what it's called off hand) which seems to be ok, other than that I would go for 8"/20cm.
If she's following pet shop advice I guess she may be feeding a chunky syrian type mix which they often don't enjoy or struggle with, Burgess dwarf hamster harvest is readily available most places & they seem to like that, expect the grass pellets.