7 weeks old aready!!!!! Holy cow that time went fast! Has there been any recent pics posted that I may have missed?
As far as a bath goes, IMO, I'd wait. They're still pretty young. With my one litter so far, they didn't get a full-fledged bath until the day before they left for their forever homes. They were about 10-11 weeks old
How about just doing a light once over with a warm washcloth and periodically washing their bottoms and feet? And of course keeping their potty area as clean as you can.......which I'm sure you do already.