SC Military Spouse

[Possi]

This is my client in the military. He is a SC resident for tax purposes. He and his wife are both from SC, but until now she has had to pay taxes to whatever state his military career has placed him. 

This year, she can stay a SC resident along with him. 

Regarding the spouse's income, some states say that if spouse's income wasn't actually earned IN that home state, it's not taxable TO that home state. Not so with VA. We tax it all. 

I can't find a reference to this particular situation regarding SC. 

Is her income while earned in CA taxable to SC because she is a (military) SC resident with her husband?

Can anyone show me where to find this?