At social events what is time off and what is not
When at social events (rodeos, etc.) this is normally considered a governesses time off, so don't assume that she is a full-time Nanny. If you would like her to mind the kids for more than 30 minutes constant care, then let her know before what you expectations are.
I enjoy employers who are upfront about expectations. I am willing to be flexible when the need arises. It makes it a lot easier to know where I stand.