The Americans with Disabilities Act doesn't differentiate between a "center" or "FCC". Whenever federal law says "daycare center" they are including centers, FCC, after school programs, etc. "The ADA prohibits
family child care providers and child care centers from discriminating against a child, parent, or employee based solely on his/her disability (such as denying admission into a child care program). The ADA requires child care providers to make reasonable accommodations for all children." Here's that sheet from the Public Counsel Law Center,
THE AMERICANS WITH DISABILITIES ACT & CHILD CARE PDF
Charging a family more because a child has a condition or disability is opening yourself up for a potential lawsuit unless you have to hire extra staff specifically for that child. Should this family decide to fight you in court it will be your responsibility to show that this child's diabetes doesn't fall under the Americans with Disabilities Act and that could be a tough fight. The Americans with Disabilities Act doesn't list specific conditions "Because each child is unique and has unique needs, no single approach to caring for children with disabilities can be applied to all children, or even to those with the same disability". So in other words, it's based on a case by case basis but courts don't typically side with the person going against this Act.
"The Americans with Disabilities Act (ADA) defines a child with a disability more specifically as one who has a physical or mental impairment that substantially limits the child’s ability to care for herself or himself, perform manual tasks, or engage in any other “major life activity,” such as walking, seeing, hearing, speaking, breathing, or learning, in an age-appropriate manner."
The sheet that I have goes on to say "]The kind of disability a child might have can vary greatly — allergies, moderate retardation,
diabetes, cerebral palsy, or even a terminal illness
may each be considered a disability under the ADA." When dealing with the ADA it's best to tread the waters very carefully. From Childcarelaw.org
Caring for Children with Special Needs: THE AMERICANS WITH DISABILITIES ACT AND CHILD CARE
The only way that you can safely charge more without risk of a lawsuit is if you for example, feel like the staff member that cares for this child will be overwhelmed so you hire an extra assistant for this child and either bill the parents for this extra help or you can raise their rates a bit to cover a portion of the extra assistant and "eat" the other part of the cost.
On a side note, I can just imagine how intimidating this task and responsibility can seem to someone that has never had to deal with it. Are you open to the option of personally training and observing your staff member until she feels comfortable? Or of having your staff member trained by either attending a class or by scheduling an appointment with the child's physician so that she can learn the ins and outs (at the expense of the parents)?