Just to clarify, your daughter has already filed her own tax return but you want to know if you can also file her on your tax return as well, as a dependent?
Please click the following IRS.gov links to learn if you need to file a tax return:
https://www.irs.gov/help/ita/do-i-need-to-file-a-tax-return
https://www.irs.gov/newsroom/who-needs-to-file-a-tax-return