Besides it'll make crappier earrings when she divorces you. I can hook you up with a spark plug washer or cigar band.
I guess you should buy something really big. Couple carats at least. Go for broke and get used to it now.
And at the alter when you say "I do", from then on the only two words she expects to hear are "Yes dear".
And remember, whoever said that you couldn't close a hole with a ring was never married.
If she loves enough you size won't matter. hahahahahaha I even made myself laugh with that one!
The only other thing I can add (not true I could go on)is don't pay cash for it. Put it on your credit card and then she can help pay for it later. What's hers is hers and what's yours is at least half hers too.
Wedding ring $400
Wedding dress $1500
Flowers, 7 bridesmaids dresses, cake, champagne, rehearsal dinner, sit down catered meal for 500 of her closest friends and relatives who you hope you'll never see again, honeymoon, etc, $15,000
That ring shoved up your rear and you spending your honeymoon night alone, slumped over a bar - PRICELESS!
Seriously, what would you want her to pay for a hunt for you? Multiply that times 2 or 3 and you've got a figure she would like to see you pay for her ring.