Thanks for the thoughts and comments.
I think the problem is with the camera – we have had the same symptoms with multiple batteries. I have multiple chargers and can’t seem to trace it to either of those units.
The camera goes from working fine one minute to being completely dead.
I think she bought a Nikon battery, but I didn’t check.
I suppose to triple check, I could use my d300 battery in the d70, but was reluctant to do so under the theory that the camera might have some impact on the good battery, depending on the nature of the underlying problem. Is that a realistic concern?