Oh Lori, don't worry, I was exactly the same when I separated my first litter. Mum will settle down again with the girls, and the boys will be ok, they will look after each other.
Keep an eye on the little one, if you want to post pics here should the paw not be getting any better. Babies can often have an issue, sometimes from being born, sometimes while in the nest, sometimes when they're tiny mum over grooming a little. They are so delicate that they can be damaged. my Whizzbit has a severed facial nerve that he came out the nest with, he could have been made that way, or it just could have happened.
If your little one is getting about ok, doing all the hamstery things they should be doing, and adjusting well you have nothing to worry about. If they are in distress or struggling too much then you'll need to investigate further.