I would not be too worried then as if see eating well as well as what you just answered to my questions I'd say she is just a young inexsperanced mum.
Let her have the pups where she wants whithin reason of course as in safe & cleanable. You may just have to do the hard yards with her for the first few days just being there for her to keep her settled.
I would be adding devac puppy milk replacer to your bitches feed diffently & some chia seeds would be good too. I feed my bitches at this stage of mothering 3 times a day & leave them with high quality dry bits & water at all times. Add some eggs to her dinner a few times a week as well she'll need all the nutrents high foods she can get at this stage as pups are doubling in size every few days & she is their only nurishment.
If you continue to have any issues of her not staying with pups I reccomend a crate that she has no choise & her spending feeding times in there with litter & door left open so she can lay at door way when she needs to at all other times. But I doubt you'll need it just stay calm & reasure her but don't muck around with her pups too much if possible at this stage.
Give the pups cord a dab with idone also.
I used to find lavander oil would sooth mum dogs & a warmed devac milk with an egg mixed through too.
Dogs make everyday life enjoyable...........