If her breathing is real shallow, it would be very hard to see or be sure. Hey I've never heard of anyone doing CPR on a snake but you might have
nothing to lose? I've raised mice for many years & sometimes a new mom doesn't clean up the babies...I find them blue & dead, no movement,
but I clean off the membranes & have used my finger to pump their tiny chest area...believe it or not, many do start to breathe & turn pink & survive.

That is just so sad to lose any pet this way...I hope the others are all ok, but I also hope that Lucy just somehow wakes up...