If her profile is still up, then it's a programming bug.

Send a message to Admin about it, or wait a day and try again.

Step 1. Are you starting at someone's Profile?  
Step 2. Are you then clicking the big blue "Review Provider" button on the upper right?
Step 3. Do you get partially filled in Review form or is that where you are getting the error?
or
Step 1. Are you starting by clicking the "Submit a Review" link to get a blank form?
Step 2. Are you getting a page that says:  
"Submit a Review
Is this an Existing Provider?
An Existing Provider has a Provider Profile/TER ID.
TER ID [                      ] Search
Step 3. Do you enter her Profile number and hit "Search"? Is that where you are getting the error?
.
Are you sure you are entering her correct Profile ID number? No typos? ID number and not some other number from her Profile page? Are you comfortable telling us who it is (Name or Profile ID)?  
.
Can you go back and try "Method One":  
Step 1. START on her working Profile Page.
Step 2. Click the "Review Provider" (as in "Review THIS Provider") button on the upper right and  
Step 3. Let us know if that works.

Impposter told you to do, which is  all correct, WHILE you are her profile page, copy the ad link.  Then when you click the Review Provider on the upper right, the next page that comes up will have a field to paste it there.  A review will not be accepted without a working ad link.  

 
Also, while you are writing the review, it will autosave the draft periodically, but not in real time, so what I do is at the end of each paragraph, I click Save Draft to preserve everything I have written so far.  If you want to leave in the middle and come back to it later, Save Draft is also used.  When you return to the draft, click on the "pencil" icon rather than the name to keep writing/editing.