Ah, too old. Ok. Well, give the doe about a day after kindling to figure out what to do. If she doesn't you can always keep the nest you make with the babies in the house and take the box to her to feed once a day. That is best case scenario. Babies don't have to be in the cage with mom and they only feed once a day anyway.
Other scenario is she ignores her kits and doesn't figure out she's a mom and needs to nurse them. Two options--hand feed the kits (there is a formula recipe on RT) for several weeks, or you could dispatch them and rebreed the doe and try again. Many breeders on RT don't expect a first time mom to succeed with a litter, it's just too new to them. Many times, those breeders are pleasantly suprised.
So I'd just wait out the doe and if she seems done making a nest, make the nest for her, line it with lots of fur, and take her babies out to her tomorrow and see what happens.