Welcome to the forum!
As a breeder I can answer your questions,speaking from my own experience. If they are covered up, with her fur and straw, then yes, she is tending to them, for the most part. Generally speaking, my does that don't intend to care for their young, don't even bother to cover them up, and thats when I take over. For the first 24 hours, some buns, or most buns as I am told, don't nurse.
I am also told that you will *never see a mother rabbit nurse*.. while that may be true, I think all of mine are so use to me, they do it when I am in there, so either mine arn't shy at all, or thats just an old wives tale.
By tommorrow morning, she should have fed. Check the babies.. if they have lil round tummies, they have been fed. Mine are all baby Cali's, which we call pinkies when they are newborn kits. You can actually see the milk in their tummies when you turn them over.
There is a rule about not messing with babies as the mother will reject them, some tell you to put a dab of vanilla on their heads and a dab on mom's nose, or use baby powder, I have never had to do either.. like I said.. mine are just use to me I guess.
I think like people, all rabbits are different.. some of mine even shove their babies to me to look at..so I guess what I am getting at is the vanilla orbabypowder trick is kinda a judgement call, based on your rabbits temprement, as in if she gets snippy or hostile when you reach in..