While NC may not have a legal seperation status if you are living seperate and meeting the requirements for your 1 year seperation you are seperated. See the irs excerpt below.
Topic 353 - What is Your Filing Status?
Generally, your marital status on the last day of the year determines your status for the entire year.
If you are unmarried, or if you are legally separated from your spouse under a divorce or separate maintenance decree according to your state law, and you do not qualify for another filing status, your filing status is single.
Generally, to qualify for head of household status, you must be unmarried and you must have paid more than half the cost of maintaining as your home a household that was the main home for a qualifying person for more than half the year. You may also qualify for head of household status if you, though married, file a separate return, your spouse was not a member of your household during the last six months of the tax year, and you provided more than half the cost of maintaining as your home a household that was the main home for more than one half of your tax year of a qualifying person.
If you are married, you and your spouse may file a joint return or separate returns. If your spouse died and you did not remarry in the year that your spouse died, you may still file a joint return for that year. This is the last year for which you may file a joint return with that spouse.
You may be able to file as a qualifying widow or widower for the two years following the year your spouse died. To do this, you must meet all four of the following tests:
You were entitled to file a joint return with your spouse for the year he or she died. It does not matter whether you actually filed a joint return,
You did not remarry in the two years following the year your spouse died,
You have a child, stepchild, or adopted child (a foster child does not meet this requirement) for whom you can claim a dependency exemption, and
You paid more than half the cost of maintaining a household that was the main home for you and that child, for the whole year.
After the two years following the year in which your spouse died, you may qualify for head of household status.
More detailed information on each filing status can be found in Publication 501, Exemptions, Standard Deduction, and Filing Information.