wow you have a handfull and a half
If it was me i would keep an eye but not interfer too much- mom is probably very confused at the moment. My 2nd kitten used to try to sleep in the cat litter tray when it was changed , im sure its the square shape that represents security to cats as the fav bed is the bottom half of a budgie tray with a rough towel in it. its taken weeks for them to discover the "posh" bed with padded cushions and soft lovely blankets.
If you have aspare litter tray you could try putting a towel in that and see if mom finds that suitable?
if mom was feral then it must be very strange being given all these lovely new stuff after living on the streets perhaps?
Im in nooo way a cat expert so only giving thoughts on what may be happening in moms eyes. disruption in any animal too cancause them to reject babies so just keep a close eye on who is getting fed , if you notice the mom definately rejecting kittens then you may have to hand feed with the special kitten formula- Im not sure this is the case though by what you have said so far.
Id keep the obsevation as quick and quiet as possible at an unthreatening distance but at regular intervals-also maybe use a pair of cloth gloves rubbed with moms scent if possible maybe? if you do have to handle akitten in case she is a nervous mom.
Im thinking of fostering moms wth kittens too for local rescue so will be reading on how its all going with your new feline family-good luck