Hi Peggy,
I see you're in the States which makes matters more complicated

I suppose you mean who else was living with your grandparents at that time?
Normally you could use electoral registers but that would only show adult males, if you're looking for children that doesn't help. Street directories, again, would only note the head of household.
If you could tell us specifically what or who you are looking for perhaps we can find another resource,
Jane