I would assume that you would keep it 90% work related. Occasional insights to ones personal life is ok. I think that adds a sense of character and realness. When I say realness I mean not just some robot behind the desk type thing.

I would think that mentioning you were busy is a good thing, but I would think to never state how tired etc you are. As a prospective client, I would think that she is too busy to take on my work or wouldn't have the time to focus on my needs.