K.L.
This is tough. You just have to be nice, and honest with her. It's not doing him any good getting mixed messages. Just tell her what works for you when you have him, maybe she will get the hint. I just talked to my sister about this the other day because she runs in home daycare. She has a fear that she will be the only one doing potty training for her youngest child. It really too bad that it's not always "team work". The child suffers because of this. I know it's not always easy and when Mom gets home at night she just wants to relax...but you have to do it!! Keep up the good work, I applaud you. :) You are a good auntie! Honesty is key... Good luck and keep us updated!!
K.