Retirement tax questions

Yes I am claiming her as a dependent, but if I check YES to Gross earnings more than $4300, the Child Tax Credit is removed.  If we are eligible for the Child Tax Credit, I would like to get it, but if we are NOT eligible for it, I want to follow the 'rules'.  My daughter has major health issues, and she is not able to work.  She does receive a little more than $900 a month in SS Disability benefits.