I think you handled that exchange perfectly and she was definitely trying to apply guilt -- good for you for just ignoring those comments!

Custody agreements I'm familiar with are often that father takes kids every other weekend plus 1-2 nights per week. You taking them all weekend every weekend does not seem reasonable to me.

Married 18, Together 20, Now Divorced
M: 48, W: 50, D: 18, S: 16, D: 12
Bomb Dropped (EA, D): 7/13/11
Start Reconcile: 8/15/11
Bomb Dropped (EA, D): 5/1/2014 (Divorced)
In a New Relationship: 3/2015