Retirement tax questions

Thanks for your reply.  Turbotax states that if a child had unearned income of more than $400 and a gross income of more than $1150, they are required to file a return...I'm so confused.

 

If she files a return, she does get a modest refund but we pay hundreds more in tax, since if she files a return we have to include her income in our household income when determining the allowable Advanced Premium Tax Credit for our health insurance.  

 

Please advise!  thanks