I have a 21 year old daughter. She is student working part time. Income is $2,500.00. She filed tax return as independent.

Now I am married. How would I file and claim her as dependent? I have not filed my return yet.

Does she have to file 1040x? And how to change her status to be dependent? I read and saw the section about claiming dependent, but do not know how to fill it out.

I need help from tax gurus. Please help.