I am impressed...this is usually where a guy just loses ground after gaining it...
If she tries to take the kids anywhere they don't want to go then I would call the police...basically the police would tell her that she is free to go but she can't just take the kids out of their home...
I would also be tempted to talk to the kids alone and let them know (like they don't already) that mom is really upset and if she does take them some where else to live to just be calm and call you when they can, you will "arrange" to get them home if that is what they want...
Also remind them they don't need to be afraid, you will not hurt their mother, you will protect them, you will be there for your family...but if mom wants to leave she can, doesn't mean she will stay gone just like with you, she may return...her choice.
Good at dodging her bullets...good call on telling the kids in front of her what she might do with regards to calling the police...it is good that they see one rational parent...this is your best defense...
I would also think about locking my room but know that on the inside doors it only takes a good kick to open, not something the neighbors will see (like a burglar breaking in from outside)...but it might slow her down while you call 9-1-1 if she really blows a gasket and goes balistic!
