Part of it may be boredom, the other part is that rabbits just love to dig! Even a happy, well-adjusted, spayed, rabbit with plenty of things to do will dig. You might consider geting a cage with wire on the bottom and just putting resting pads in the cage so she does not get sore feet from the wire. Then she cannot dig at the bedding. Those type of cages are more sanitary, too. You can still have the litterbox in the corner. Or is that what she is digging at? Baby bunnies are pretty hyper compared to adults, too, so once she is older and spayed she may settle down a lot.