I would make sure the 'new babies' get a chance alone at someone's teats. If you are going to allow the other to nurse those babies, take the real babies to away for a few minutes so the new babies can get a chance to get used to sucking. If the mom does end up nursing them all then make sure her diet is awesome, that's a lot of extra babies. You may find that the alien mom gets into it in a few days, maybe not, I would call the vet and see if they have suggestions about how to get her to bond with her babies better. It is a weird situation but thankfully you have another nursing mom that is into it right now! Keep us posted, this is interresting to me.
