where is she domiciled (her permanent home/resi)? If it's NJ, she's a resident and it taxes their resident's the earnings of those working in other states.
link to NJ instructions
https://www.nj.gov/treasury/taxation/pdf/current/1040i.pdf
Married/Civil Union Couples. If you are married and file
a joint federal return, you must also file a joint New Jersey
return. If you file separate federal returns, you must also file
separate State returns. However, if you are a partner in a civil
union, your filing status for New Jersey may not match your
federal filing status.
If one spouse was a nonresident during the entire tax year and
the other spouse was a resident during any part of the tax year,
the resident can file a separate New Jersey return. The resident
calculates income and exemptions as if a federal married, filing
separate return had been filed. You have the option of filing a
joint return, but in that case, your joint income would be taxed
as if you both were residents.
