Still no. And I would offer nothing, and walk away.
Jared is not my idea of reputable, esp not for diamond sales, nor are they an independent appraiser who will tell you what you really bought, they're a maul chain. And if you take it, it's yours and she's gone from your life, and if she sold you something junk, or worse, fake, you're stuck with that and your money is gone. Then what? You are stuck with a fake or low quality ring and your money is gone and you have zero recourse.
What is your total budget and we can help you find the best diamond for your money in a simple setting. In a year you can reset it into something flashier. Don't waste your money on something that isn't confirmed quality. You can get a nice diamond from a legit online vendor, and we can help you do so. I think you're getting caught up in the perception of a "great deal" from these craigslist and ebay listings. Some might be legit, but mostly they're probably not, and probably using stolen photos of someone else's stuff to lure you in.