It was a good call on the agency's part, OP. This candidate may have been nice, but she isn't professional at all.

PP here - thx for the update OP. I think this was a good call on the part of the nanny. I think this would have been far more of an issue than you were even starting to envision.

For her to have invited you to a church event during an interview really should have told you everything you needed to know!

Hope you find someone great.