- Yes, if you are a US resident for tax purposes, you can file jointly with her. You would need to make an election to claim her from a nonresident to a resident. For instructions, click here Nonresident to resident
- Yes, filing jointly usually gives you a bigger refund. To see the comparisons between filing jointly and separately, click here: MFJ vs MFS
- If you both file jointly as residents, you are required to report her worldwide income including those from India. If she pays taxes to both the US and India on the same amount of income, you may claim a foreign tax credit on your US taxes. For details, click here Foreign Tax Credit.
- The filing requirements of a foreign country are out of scope for advice. You would need to consult their tax authority for further clarification.
