I am trying to file an amended return for a person for whom I did not prepare the original return.  She wanted to save a few bucks and went to Credit Karma.  She did not file a Schedule D with her return

How do I enter this?  She has an existing file.  Do I need to re-enter all of the information, or can I just do a 1040 X showing the changes?

Can I file the Amended Return online if I did not file the original return?