Originally Posted by Blackcat31:
There is your answer then.... just tell her you considered it but after much thought, just can't open that much earlier for one client.
I'd end the e-mail with something positive that leaves the door open...suggest that should she ever have a change in work hours and have such hours that fit into your routine, you would be happy to re-interview and try again.
This is how I would handle it. If I were her, I'd much rather you cancel the interview and not waste my time if you. I don't think there's anything unprofessional about telling her that you've given thought to her request and find that you can't offer those hours at this time.