This may not be practical, but maybe you could spend time with her kids for her(really, for them) it sounds like she is frustrated, overwhelmed, and doesn't understand her role as a parent. It is something she needs to learn.
Most likely the kids will not be taken away from the family. If you want to help, maybe help the kids directly even if it is only a one time thing. Do something to help them feel love and acceptance. It is amazing how well a child can remember a single incident which impacted them.
Tell them something positive about themselves. Something to counteract them being told they are naughty all the time. Even if all you said was "you are such a nice young boy. I like you.' That will go far in the heart of a child. They will remember the person who believed in them.
It is unfortunate the number of "detachment" parents out there...