I'm with dandy. First things first. Keep the kids safe, and maybe you can share some recovery insights with the mom.
Just so you know, CPS seldom swoops in and removes children at the first sign of a problem. They WILL, however, intervene in a way that keeps the kids safe. That may involve her having to commit to a recovery program, have a responsible adult there at all times when she has the kids alone (until she is safe to parent them), etc.
Please do it--there could be tragic consequences if she passes out while they are in the bath, or leaves the oven/stove on, or one of the kids is injured and she tries to drive them to the hospital, drunk.