Pine shavings are not recommended for buns, because they give off fumes that are unhealthy for bunnies, especially for babies because they’re smaller and more sensitive. You can use aspen shavings instead, or just hay and shredded paper. If the mama bun isn’t happy with the bedding, she might throw it out and rearrange it. That’s part of normal bunny mamahood.
I just want to give a quick reminder of the BB forums’ rules: The subject of intentional breeding is prohibited. If you want to discuss breeding issues, rabbits online http://www.rabbitsonline.net/ is a better place for your questions. Oops litters are a different issue though, and we do like to help with babies and mamas if we can, but most of us here have very little experience with rabbit babies.
Here are a few potentially useful links from our resources page:
http://www.bio.miami.edu/hare/surpriselitter.html
http://www.rabbit.org/care/babies.html
http://www.rabbit.org/care/newborn.html
http://www.mybunny.org/info/caring-for-newborn-baby-rabbits/