We took in a pregnant foster hamster in November, the pups are seven weeks old tomorrow so I really know how you feel.
You're right to avoid disturbing the nest. Mum may benefit from some extra protein, things like mealworms, scrambled egg, chicken... Be careful not to provide too much fresh food, but some of those things can be really good for Mum.
Milky foods like porridge can also be worth offering sometimes.
Just to ask, was Dad taken out before or after the litter was born? If it was after you could have another litter on the way later.
Just leave Mum to it for now, when the pups eyes are open you can possibly start handling them if Mum seems ok with it. At four weeks of age they'll need to be separated into single sex groups, if needed the girls can stay with Mum and Dad will probably accept the boys (the male pup from the litter here is living with his Dad permanently).
There's no guarantee it won't damage Mum's health, litters in general do tend to shorten lifespan and Mums can suffer a lot from a litter. All we can do there is make sure she's got plenty of food, water e.t.c and trust her to care for herself at the moment.
And er... Inbreeding can be a problem, but as long as there're no problematic genes (we had a risk of anopthalmic white pups in our litter) the pups should be pretty much ok. One generation of inbreeding rarely does much harm
The litter we had started to leave the nest at 10 days, eyes started to open around 12 days. Oh and one thing - Try to not panic if at first one looks unhealthy. The male pup in our litter really scared me the first time we saw him but the fears were groundless so its worth waiting before you worry