Let her crash down in front of the children... They will see it eventually and make their own minds up. The focus is you being the better parent - Learn from her screw ups and be the rock.
This is so true and just happened to me last week. I got my kids back after 5 days away. I got home from the store and my daughter ran out to greet me. I could tell something was wrong. She asked for a hug and started crying. I ask what's wrong and she said "it's mom. She's miserable and yells at me all the time. She's just not the same person anymore." So I hugged her and validated her feelings and let her know that I am here for her whenever she needs me.
