There are a number of questions that need to be answered before a lawyer can give you advice:
(1) Has there ever been a child support order for this child before? If so, in what State was it entered?
(2) If this is the first time that a child support order has been requested, where did they file the petition - in NC or FL?
If it is in FL, then you will need to speak to an attorney in FL. Most states are similar in their laws regarding child support. In NC, you would be required to pay child support until the child is 18. If this is the first time child support has been addressed for this child, then they may be asking for support going back three years.
The only time it matters whether they are making sufficient progress in school is after the child turns 18. In NC, you won't be required to pay child support if the child is 18 and has dropped out of school. If the child is in school, then you could be ordered to pay until the child turns 20.
I have attached a link to the NC child support statute for establishing child support. You should seek the advice of an attorney before appearing in Court and making any statements regarding support. However, if this is indeed your child, you should be paying support, and I hope that you will be glad to do it!
The information you obtain from this post is not, nor is it intended to be, legal advice. No attorney can give legal advice without a full consultation wherein the attorney is able to get as many facts as possible. Any information contained in this post is for informational purposes only. Please seek the advice of a competent attorney in your area to get legal advice specific to your facts.