You can probably get a decent 0.8 ct stone in a simple gold solitaire setting. I recommend putting more of your budget into the stone and then if she wants a fancier setting, upgrade in the future when budget allows.
Here's an example stone - my search wasn't comprehensive so there may be something better out there but this will be way better than what Kay will have
She made it clear, she didn't want a simple solitaire ring (that's what I prefer) I've been on Blue Nile, JA and Diamond Direct (local jeweler). Going with a 1ct total weight, using the halo setting roughly $1500 and finding a nice rock for the other $1500
Changing my cut from round to princess or cushion I can go up color/clarity. Don't think she cares about the shape between those