I need to add my 20 yo college student to my amended return? No one claimed her and when she filed her own return she said that someone else would claim her?

If she meets the requirements to be claimed as your dependent, then you can add her as dependent on your amended return. Please wait until your original return has been processed. You can e-file your 2020 amended federal tax return, but most states require amendments to be printed and filed by mail. Please see How to amend a tax return for instructions.

If you want the tuition and education credits you need to file her 1098-T on your tax return.