I think it's reasonable for them to contact her and ask her questions, but they should go through the lawyer if she wants them to.
Refusing to talk to someone's laywer is bad enough, but saying they're going to pounce on her uninvited out of nowhere is completely over the top.
If the require some documentation that someone is representing someone else, maybe they should also accept mailed and/or faxed documents for proof.
I find it reasonable for someone to assume that their participation in a currently legal (but controversial) project would be a potential reason that the FBI wanted to question you.