OP- what was the 'old photo' that you tried to tag her in that may have precipitated her actions? I know when I first joined FB, I did not appreciate being tagged in old ES, MS, HS photos by others - some were inappropriate, or reminded me of my awful MS hair cut

- but mostly I didn't like not having control over what was posted with my name attached. I learned to fix my privacy settings to prevent this, but I can see others getting off FB entirely.
Also, agree with all the posters above - FB causes more drama than it is worth.