Question 1: Is she required to file a nonresident Maryland return.
Yes, she must file a Maryland nonresident return if you are required to file a federal return.
According to the Maryland Department of Revenue, a taxpayer is required to file if:
You are a nonresident of Maryland and you are required to file a federal return and you received income from sources within Maryland. If your federal gross income is more than the federal minimum filing requirement for your filing status, you are required to file a Maryland return, even if the income attributable to Maryland is less than the federal filing requirement.
Please view the Maryland link below for more information.
https://forms.marylandtaxes.gov/current_forms/nonresident_booklet.pdf
Question 2: How to file this type of state return when filing as married filing jointly.
You should file as married filing separately on the state return since you have separate residency status. Follow the directions in the TurboTax FAQ below to do so.
https://ttlc.intuit.com/replies/3301995
