> She is having puppy food, lactose free milk and plenty of water.
As already said, newborn puppies don't need to cope with teats loaded with milk. With continued nursing, the milk will come down and with only 5 puppies to feed, she should have no problem providing for them. If the puppies are quiet after feeding (there may be little noises as they drain the teats and move to another) and gaining daily, I'd suggest you have nothing to worry about. Re 'puppy food' - I don't know why people think this is for a nursing mother when it's for PUPPIES once they move onto solids. Provided her normal diet is a good quality food and maybe fed more often through nursing again she should be fine. I don't think she needs milk either. Fresh water of course but the only milk I ever gave my bitches was maybe goats milk which dogs tolerate well as it's close to bitch milk in make-up. And only then to clean up after the puppies have been given milk as a start to the weaning process (so they learn how to lap). You could add a little more meat, or even something like scrambled egg to her diet but really the top quality normal food she has should be adequate.
The time through the first 3 weeks should be the time you catch up on a bit of sleep, keeping an eye on things - your work begins with weaning, by the end of week 3!!
If you are worried that the puppies aren't gaining, or are noisy, you may need to think about supplementing - most of us would buy in some replacement bitch milk, just in case, but again with only 5 puppies, I doubt you'll have to be doing anything other than making sure the litter is kept warm and let mum get on with her job.