How can I get the ring size of my wife without a trip to the nearest jeweler, (gas is $2.85 ).

Ask her?

ha^^

My wife and daughter bought a ring sizing set off of Amazon

Make up a story that your buddy is buying a ring for his wife and not sure how to get the right size.

Had to do this once a very long time ago. I bought a long skinny funnel and slid one of her rings on it and marked right above and right below with a Sharpie. I took that the the jeweler and it was no issue getting the size right.

Acquire a steel ring mandrel. You can check the size of existing rings which fit, see the difference between narrow bands and wide bands on the mandrel, and tap mis-shapen rings back to true round.

The last item you can also do with a pool cue and a Bic lighter, as got me points in a New Orleans bar one JazzFest

If you want to email me your address, I can send you my ring sizing set. Got it off Amazon.

Here's an idea: buy the ring from Dave Truong. All he needed was a photo of my wife with her hands showing to size a ring perfectly for her.