The chronic lung condition would be my concern. As a home care provider you are one person caring for many needy, dependent children. When one child has medical issues that require extra time and concern then it can take away from the others and can add stress. I would think that the chronic lung condition might put the child at greater risk for catching (and further complicating) common colds etc.

It kind of sucks for the family because while as a caregiver the child is not a great fit...a centre based daycare is likely a riskier environment for such a child (more kids more germs etc).

If this child goes into medical distress how will you handle it, and the other children in care?