At 7 to 10 days, pups are supposed to double their birth weight and all pups have achieved this. Weight gain fluctuate from day to day gaining a small amount or a large amount but they gain daily. Their weight gains will slow down when they are mobile as they expel more energy.
It will be fun to see them mobile.
I make their whelping box and often Willow makes a mess of it. I have to laugh.