Hi Danielle,
I hope you are well today and thank you for your question.
The plugin provides option to search within particular post and its comments content but not by particular commenter.
I saw messages communicated with you on email.
If you have configured the search form such way and still not getting result then as requested earlier would you mind if I log in to your site and do some troubleshooting? If this is ok then could you please share me your site log in details privately by checking the option “Set as private reply” when replying to this topic?
Also please tell me where on your site you are using search form.
Best regards,
Ivory Search Support