One thing I would suggest is to look at some of the other daycares near you - put your postal code into daycarebear or look on kijiji for your area. You want to get a sense of how others are setting things up as that is what parents will be comparing you to. I totally understand the Montessori concept and around here a Montessori preschool is preferred by many parents. However for those that don't understand the philosophy they see things as too minimalistic and simplistic. Make sure that things are mixed or explain your day differently in the sense that if they only have Montessori in the morning and nap all afternoon parents might wonder when they get to play with the toys. Show all that you have but emphasize the access to Montessori approved activities and maybe include a page of info to explain the philosophy in your handout and how you incorporate it into your program. Basically in most areas it is not a draw or a deterrent as parents honestly don't really care. They care about price, location, hours pretty much in that order.
It can take a long time to get started so do hang in there. I would not mention why you have decided to stay home with your child as again that might be deterring families that think oh medical needs = medical appointments = needs time off.