reply to that e-mail and just point out that terrible comma splice. Woof.
She is right, though. You do technically owe her for those sunglasses. However, you need to make her prove the actual value of the sunglasses you lost, because it is not full-retail price. Make her show you what identical used sunglasses in similar condition have been selling for recently on the secondary market. If she tries to cherry pick and find the highest asking price for a used pair, go Rick Harrison on her ass. Oh yeah? That's probably why they haven't sold, BOOM.