Is it possible to add a review from a home owner who has now become a member for a sit that we did for them in the past (before they were on THS?
I don’t think you can do so the normal review way but you could as a reference.
Maybe you could ask them to write a review (or use a previous one from another platform) and take a screen shot to include in your photos.
To me, it wouldn’t make sense for THS to allow anyone to add reviews for sits it can’t even know occurred.
Similar to @Maggie8K, I think it doesn’t make sense for THS to post a review for a sit that didn’t happen on their platform.
However, you can definitely have them write a review and use it in the references section of your profile. That’s what we did for sits that predated our using THS.
But to straight answer your question, no, there’s no public option available to us that I’m aware of to do what you’re requesting.