Follow-up,
I took everyone's advice, except to get a mustache and wear a beret? Before the client arrived I cleaned up my studio, put a screen between studio and my living area, boiled water for tea, put on a pot of coffee, set out cookies. Set my portfolio on my table, made sure all my portraits were hanging in clear view, laid out contract and pen, set up the photo shoot corner with toys so that little Claire could see what it would look like when she came back on a Sunday afternoon, and I S L O W E D down my breathing and pretended to be a true professional artist (if you don't feel it fake it - learned that years ago when I owned my own business).
Well, the client came with his little girl and his wife (who was not sold on the idea) By the time they were ready to leave they had asked many questions about doing portraits of their two boys also!
And little Claire is BEAUTIFUL and did not want to leave!! They are scheduled for the photo shoot in two Sundays, pray for bright sky in my northern windows...
...thanks for your moral support, I depended on it last night!