Source; Im a financial aid counselor for a local private university.

Per federal regulations when your Finance fills out her FAFSA for the 15-16 academic year( pending she is starting in the spring of 2016) if she is 24 or older, active military or IS married she will be concerted independent and your income may not be looked at. It really depends on if you are providing at least half of her support for the past year. Taxes and Federal Financial aid are separate, but still conjoined in certain areas. ( confusing I know) If you walked into my office today and said all of this my question to you would be when does shes plan on staring school? In the spring of 2016 or the fall? If she is not starting till the fall of 2016 and by then you are married, she will still be independent but your income will be taken into consideration. The only real problem this brings is will her federal pell grant be lessened by your income? ( making 100k a year, it most certainly will be) Also if the university offers any need based aid that could be affected as well. Since you two will be making good money for only 2 people she probably wont qualify for any of those free funds. Now on the other hand it will have no effect on her student loan eligibility or merit scholarships. Since both of those are not tied to personal finances. If she is planing on going to school in the spring of 2016, she could also loose her free aid if you're providing more than half of her support during 2015.

To answer your question about how to list her on your taxes is separate than financial aid. Even if you dont list her as a dependent on your taxes the university she goes too might still have to look at all the support you are giving her and award according based of that. Theres a verification process the Feds make students go through when their FAFSA and taxes dont match. So to my knowledge there's really no way around the issue if you are supporting her as of now.