I do what Mamma Mia does. I tell the families before they even come for the interview that i have other interviews and that I am looking for the best fit for my daycare, so I will get back to them once I have met with everyone and we can see if we both think we are a good fit for each other. I actually usually do have more than one family interested at a time, but if I didn't I would still probably say this so that if they are not a good fit, it is easier to send them on their way without hurt feelings.