If you're both residents of SC, and your wife's work is performed 100% remotely from an SC location, then her income is not taxed by NC, and there is no need to file an NC tax return. (Her income is of course 100% taxable by her home state of SC.)
A handful of states tax non-resident remote workers, but NC is not one of those states.
NC taxes the work income of non-residents only on work actually (physically) performed within NC.
If NC taxes were mistakenly withheld from her pay, she would have to file a non-resident NC return on which she declared zero NC income, in order to receive a refund of those taxes.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
