Tracy, I think you should wait till all the pups are gone. I'd too be worried about something being brought into your house and maybe passed to the pups. But you know what you're doing and if you can keep the newbies quarentined from the rest, then by all means do so.
No matter what you do... I know you'll put your entire heart and soul into what ever dog/pups you'll be saving.

I'm sure you'll do what you think is best for Lady's pups.

In Roxie's picture on PetFinder.. doesn't it look like there's more than 5 pups in the picture? I swear I can count 7 pups!