Problem with buyer over missing piece

[letergo]

I sold a small china figurine of the king of hearts, Walt Disney classic collection, new in box, never taken out.

Buyer states it did not contain the wand in the king’s hand.  I apologized and told her to please return for full refund including return shipping.

she said no she would keep it, but would I take $10 off.  I said again, I will be glad to give full refund. 
She said, I found a little bag which should’ve contained the wand, so she’s sure that it had somehow gotten left out.  I honestly don’t  believe anything was missing, but would never accuse someone of lying.

After I told her to please return, she said “Now I need to rethink keeping the king and writing a truthful review.” 

I feel like this is a threat to give bad or neutral feedback because I didn’t agree to the price reduction.

is there anything I can do?

[jonathanbrightlight]

@letergo , it's half true.  Yes, eBay requires a photo for many returns now, but it's entirely possible for her to get around that (eBay doesn't check the photos in most cases, maybe all, so any photo, even just one copied from the listing directly, will allow her to proceed).  But, she very well may not be technologically inclined and doesn't know how to do it.  eBay Customer Support will often help customers having issues with that bypass the need for a photo to be uploaded, too.