Just to say your second sow will need more feed than your first as she has much more milk to provide, increase the amounts gradually, the girls need lots of fresh drinking water too. Watch out for sore teats and that their back ends settle down and don't look angry. Do you have a heat lamp for them should they need it, as said a rail or something similar is invaluable to keep them safe and give them access to creep. The sooner they can get their own nose in the soil the better, helps mum to get a bit of fresh air when she's rested too.