Is there a method for editing PDF back to indesign?

Have you looked into using an InCopy workflow? The editor would be able to view the InDesign file and edit it directly. 

The editor would only need training on the basic feature at first, so she could be up and running fairly quickly. 

That is because PDF Comments (which is an Acrobat PDF feature) is a totally separate feature from Share for Review. The first is PDF-based and uses the PDF Comments panel; while the second is web code based and uses the Review panel or also the web browser. Too bad Share for Review doesn't have auto-edit comments. You will have to go to Share for Review and manually copy n paste or manually retype the commented corrections.

The Pros and Cons of PDF Comments versus Share for Review

PDF Comments
■ Familiar method of exporting and sending a PDF for comment.
■ The Auto-Edit comment tools automatically update text edits into InDesign.
■ PDF Commenting saves time for the InDesign user with Auto-Edit comments.
■ Acrobat Pro has a mature, complete set of 21 commenting tools.
■ Writers/Editors must have Acrobat Pro and be trained in using commenting.

Share for Review
■ The InDesign user does not have to export nor email a PDF. Share for Review does that.
■ The InDesign user does not have to gather comments from multiple PDFs.
■ The writers and editors do not need to have Acrobat Pro; just a web browser.
■ The writers and editors only have 5 comment tools and none of them auto-edit text.
■ Share for Review simplifies things for the writers and editors; not the InDesign user.
■ Share for Review does not save any more workflow time for the writers and editors.

You could use the “share for review” feature. It allows users to write comments on the PDF and then you will be able to directly edit the original InDesign file using these comments.

See help here: https://helpx.adobe.com/indesign/using/share-for-review.html

@garethirwin1234

You can: 

1) use an option Share for Review - then she can make notes online, 

2) ask her to add notes using free Acrobat Reader. 

Then you can preview those notes in the InDesign. 

Ooh, totally missed the point of this somehow. Best method is to send out a PDF by sharing through an Acrobat PDF. Train the other person to mark up using only the 3 main comment tools:

1. Add Note to Replace Text tool

2. Strikethrough tool

3. Insert Text at Cursor tool

When the editor makes these comments in the Acrobat PDF file, these three comments can auto-edit back into your InDesign document thru the PDF Comment panel. It saves a lot of time. I wrote a whitepaper showing exactly how it works, and it is available on https://jetsetcom.net. Of course, you can also use the InDesign and Acrobat helpx system, too.