If your spouse is a US permanent resident with a green card, then she is a resident taxpayer regardless of whether she has lived in the United States or not. She is required to file a tax return that reports all of her worldwide income and pays US income tax on it. This is part of the price of having the privileges associated with being a US permanent resident. She can claim a credit or deduction on her tax return if she paid for an income tax on the same income.
Naturally, it is almost always better for married couples to file a joint return as many deductions are limited or disallowed when married filing separately. Because your spouse is a US resident for income tax purposes if she has a green card, regardless of where she actually lived, you can file a regular joint tax return using form 1040. No special rules or declarations are required.
anything you may have read about how to file a tax return if your spouse is a nonresident alien does not apply in your situation because the green card makes your spouse a US resident for taxes, even if she does not live in the US.
