I can only back up what Raven Rexs and Zakura have said, she should not be having any extra food whilst pregnant, particulary not an extra bowl. If she gains weight she will find it very difficut to give birth and you may well find yourself with dead babies and even a dead mum. I appreciate it may have been ok for you last time but if she didn't lose the wegiht gained last time she is even more at risk now. Please listen to the advice of experienced breeders - we know what we're doing (or some of us do anyway
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Reduce her food back down to 1 bowl a day - if shes hungry give her extra hay. Do you know roughly when shes due? On average its 31 days after mating. Make sure she has access to a warm quiet area with plenty of bedding to nest in.
Why did you have to hand rear before? Did she refuse to feed them? Did she chuck them out of the nest? Knowing what went wrong last time will enable us to advise you better this time - you certainly don't want to go through the hassles of handrearing again.
It is very important once the babies are born that you leave well alone -DO NOT touch them. I know this site is full of pictures of newborns (which I completely disagree with but thats another topic) but please they need to be left alone in the nest.
Once the babies are born you need to make sure Mum is getting plenty of calcium - dark leafy greens are a good source if shes used to them, or else you can buy supplements to add to her drinking water. Once born you can increase her food ration slightly.
What size bowl is she having? Are you sure shes pedigree Dwarf lop? How much does she weigh?
6 is a large litter for a Dwarf Lop, so i wouldn't expect her to have any more than that.
I would also suggest getting your rabbits neutered/spayed and investing in some secure hutch/run locks. As Raven says, once is an accident but twice?? :?