Well, there is a good reason that i have her file her own taxes, actually 2.
Reason 1. If i did not i would file her as a dependant on my return and that would push me into higher brackets. When i started doing this years ago, i would make multiple names trying to see which one gave us a better advantage (return). So what i do is have a percentage of her SSDI being taken out as a volentary FWT and i do the same on mine. This works out with both of us getting a return on what i call the 13th month and not pay IRS. I have her file as being claimed by someone else and i claim her on mine. She make such a small amount that all of her FWT is returned to her savings account and i am lowered enough that i get a return as well.
Reason2: When she was 8, i worked with several other principal on a potential business venture. We would share in the ownership. I worked out an agreement with the others that i would work for free if they agreed that my daughter would be the owner instead of me. They agreed as i was the technical lead defining the project. Because of the potential for her to gain an income by 9 years old, i began doing her taxes and establishing her in the IRS system. Many years ago my mother was the Deputy Districtic Director at Social Security HQ in Baltimore and i was fortunate to learn some tricks with SSA. LOL
