"Mothering Multiples" by Karen Gromeda (sp?) is a great book about nursing twins (and higher order multiples). I believe it is a La Leche League publication. I consulted my copy almost daily when my twins were newborns. As many moms on this board will confirm, it IS possible to nurse twins.
I also could not have done without my twin nursing pillow. I believe it was called an EZ 2 Nurse, there are many different ones out there for twins. (I found a regular Boppy to be useless.)
Good luck to your friend. (And help her stock her freezer with lots of easy meals before those babes are born :-)