
By 5 weeks, most of their nourishment should be coming from the solid food you are providing. And we always took mum out of the whelping box when they were feeding, only letting her back in to clean up afterwards. Our girls would do this standing up for the puppies to 'comfort suckle' but as soon as she felt their sharp teeth, that was it - out please.
If she's kicking off, get her right out of the whelping room! She's being naughty! We didn't do what a lot of breeders do, remove mum at a certain age, but by 5 weeks, you are not wrong - she's showing signs of OCD!!!
For me, it's more important that the puppies get used to surviving on a solid diet from now on, than to continue to take most of their nourishment from mum. And for her, she needs to be starting to scatter her milk, which won't happen as long as they continue to nurse off her. This weaning process should be pretty much complete (onto solids) by 6 weeks, with the remaining couple of weeks for you to make sure each puppy is established in their diet and by 8 weeks +, ready to go home.
If she's still cleaning up after them (mine pretty much stopped once they knew their pups were onto solids), get in there and remove the stools yourself, before she gets to them. This is a tad over and above!!