For starters, it looks like your situation qualifies for one of the VERY VERY RARE exceptions where a married person can be claimed as a dependent on someone else's tax return. Here's the rules for the exception.
The Student:
- Must be under the age of 24 on Dec 31 of the tax year.
- Must have been enrolled for any one semester that started in the tax year.
- Must have been enrolled in a program of study that will lead to a degree or other credentialed certification.
- Must file as "married filing separate"
- The student, on their MFS return must select the option for "I can be claimed on someone else's return."
- The spouse, on their return must select the option to indicate their spouse (the student) can be claimed on another's tax return.
Both the student and their spouse must agree to this. If they do not, then flat out nobody can claim the student as a dependent on any tax return.
