It depends if the Twitter is her personal space. We're not clear on it, but if she hasn't cut the client out of her official venue of business, then it should be her right to set up her personal spaces as she sees fit.

Not really replying to you you directly, but just adding to the comment chain.

I'd be annoyed too if a client poked me on avenues that I didn't have set up for official communication. Then again, no one would be waiting ages for a comm in the first place, heh.

edit: Disregard this. Found her only listed Twitter and it's a work twitter.