@Ed-and-Susie0 hello! Congratulations for your first positive review!
I think you cannot delete a reply to a review, but maybe you can edit it for a small period of time.
To try it, go to HOST, select REVIEWS and then select Reviews by You. There you will see your last review. If you are able to edit it, you will realize it there. if not, it is ok, don't worry. You just mention about a diamond earring, it is not a big deal I think. You can just send a private message to your guest and clarify that you were aiming to send that privately.