endanger the warfare of child

ren. I am sure Germany has very strong law to protect children.
You need to document all the things she does that endanger the warfare
of her children and report to goverment agency that protect children.
Once they start an investigation, she will be walking on thin ice
for quite some time. The goverment will protect the weakest party,and her kids are the biggest victems anyway. Who knows, your action might
save some life in addition to make your life better.