The child will be flying on Spirit from North Carolina to Pennsylvania
Answers (1)
Children under 5 years of age are not allowed to travel unless accompanied by an adult. Children over the age of 2 years need to book their own seat. You'll just end up booking two regular tickets, I don't think Spririt makes a difference for minors and adults. Only infants (2 years and under) can travel without a seat booked.
Other than that, you can ask if they offer a child meal (if this airline provides a meal). Or bring some snacks for them as they will get hungry.
There are no other requirements. Just bring a few toys or some entertainment for the child :-)