Thanks you guys. You're both right. It really was a favor she was asking me for. And I could have said no.
I didn't get the sense she asked it felt like me she told you. Watch your kids don't watch them your choice. The biggest issue I have is that she did not involve you in the decision making progress.
She could have called you ahead of time when she found out about the potential work opportunity to involve you in the discussion.
"Hey Chris, this is W. I have an opportunity to work tonight and was wondering if you could watch the kids longer than normal" I wanted to check with you first before I booked it to see if you were free".
That shows respect for your time and gives you an opportunity to say "yes or no, I have plans". If she wants the job bad enough she will make other arrangements for child care.
