As has been said previously, if they made it this long then the female is surely feeding them. It could just be that it's too big a litter for her, especially if it's her first. She might have pushed those two out of the nest or otherwise neglected them while tending to the rest of the litter. I wouldn't sweat it, honestly. It sounds harsh and it sucks but that's nature and it may have been for the best if they were runts or ill or something else entirely going on. I'd say leave her alone as much as possible, especially if this is her first litter and just make sure she has food and water. Don't stress her and she should do fine once she gets the hang of things and figures out what the pink naked squeakers are doing hanging on to her, lol!

One of my females ate her entire first litter of seven and has since gone on to produce no less than twelve per litter, all of which she has reared just fine. Give her a chance and relax a bit and things will work out. Been there and done the stressing every detail part of things and it does no good. Best of luck to you and hope that helps without being too harsh.