Yes, it’ll be likely be taxable. Question is whether subject SE or not. You need more details about the nature of the payment to determine Sch C or other income. 1099-nec instead of 1099-misc raises questions 

My client received a 1099 NEC for education she is already a teacher

If the income is used to pay for tuition or other qualified education expenses such as books and required fees, it is not taxable. Otherwise it is, even if used to pay for room and board.

Let's clarify some perspective.

It's "for" education: a 1099-NEC means she got paid for her services. Or, it's for fellowship rather than services. Fellowship would be reported on 1099-Misc, so that it is Other Income reported on Schedule 1,  rather than Schedule C, to avoid self-employment tax. But if she provided services, that would be subject to self-employment taxes and reported on Sched C, along with any costs she incurred for providing that service.