Mummy rabbit will ignore them as she'll want her own space, as long as she's letting them feed, this is usually only once or twice a day. They'll start eating solid food at around 3 weeks, possibly earlier, but generally that is when mum will start to wean them off milk, by 6 or 7 weeks they should be eating solids for themselves. Make sure there is plenty of hay available and food suitable for young rabbits, easy enough to buy from pet shops. Of course lots of fresh water too. Avoid lots of greens, as they're ok for mum but the babies digestive systems won't be able to cope with it yet. They can be weaned onto greens at around 3 months.
If she does disown them or if any die she will kick them out of the nest, and don't worry about her killing them by accident or anything.
As for handling the babies if you have a good relationship with the mum she might not mind, but as a precaution wait till they're a bit older and rub your hands in the bedding to make your hands smell like rabbit when you do.
Between 8 and 12 weeks the babies can go off to new homes, plus the bucks of the litter will need to be separated from their mum and sisters to prevent any more babies.
Good luck.