The more I read about this, the more I wonder if most of them were just playing an ARG (or at least thought they did).
How good of an agent can she be if she was caught?
I'd say very good. The value of a spy is in the information distributed not not getting caught. The other problem is the vast majority of the performance data we have is from agents, who were caught, so it's difficult to compare and contrast agents who were caught vs. those that aren't. We also don't yet know what information they passed.
"possibly the worst intelligence disaster in US history." http://en.wikipedia.org/wiki/Robert_Hanssen
She was indeed a very good agent. She was very friendly and mentioned that her family had lived in France before they moved to Boston. She had a slight Russian accent (I noticed because my parents are from Russia) but I didn't ask about where she was from.
It's weird to have such a random connection to this strange story. I don't know what outcome to hope for.