try them
or at least sit and them, and pretend to paddle. Your wife is very small. I expect she will have a lot of trouble handling a typical wide, deep boat. I think your concern about tippiness is misplaced, because boats aren’t inherently tippy. Put someone your wife’s size in nearly any boat and I’d be suprised if she felt any tippiness. At her size a boat like the Tsunami SP will be totally stable. The hull shape is designed for reassuring stabilty.
My daughter is 60 pounds and paddles a 19" kayak. The first time she tried it she could climb up on the back deck without any stabilizing, and crawl back in the cockpit. For her size, that boat is totally stable. And she can paddle it very easily and fast, because it fits her. Put your wife in an appropriately sized boat and she’ll have the same ease and enjoyment.
Nate
Tippy?
Atlantic Kayak takes people out on tours who have never been in a kayak in 21" wide Romanys. They have lots of stability and for a smaller woman she will feel totally comfortable in it. There’s others too. Women do much better than men as far as feeling secure in narrow kayaks. People go the recreational kayak route not because of stability but because it’s inexpensive, easy, care free, no commitment to the sport and a summer pastime to amuse themselves.
The only drawback on NDK boats is weight and she might like something lighter ??
Willowleaf…
…offers up excellent advice. That Delta Catfish also looks very interesting. I think that you should buy one and report back to us with a detailed report 
And while you’re at it, here’s more for ya:
http://www.hobiecat.com/
Go straight to narrow
Probably she would paddle the wide rec boat for a few months to a year and then be craving something she can edge. That’s what happened to me.
She would get some useful butt time in the wide boat in that she’d become comfortable on water, but that’s about the ONLY benefit. Unless she’s a klutz, there’s no reason to wait to use the 21" beam kayak. The real sea kayak would allow her to edge it and begin working on all the rest of the skills built upon that.
Mini Vacation?
The adage of “try before you buy” is oft repeated here because it’s good advice. You say there are no kayak shops near you, so why not take the spouse & kids off for a kayak weekend? Take a lesson, rent, demo, play and get a feel for as many of the different boats as you can to see how they feel & meet your goals.
Thank you all again
I initially started this post to see if we should get the basic big box boat first and that answer is a resounding no. We read through a few times and I spoke briefly with a couple dealers today regarding shipping costs (roughly $150). The closest dealer that will order in boats at this time of year is 5 hours drive (2-5 week delivery). The closest big city that may have selection to look at is 8 hours. Not having the luxury of trying before I buy is why I am so impressed by this place. I can read reviews by people her size and my size and draw from the collective experience to find out what works and what doesn’t. We will order one of the smaller boats as suggested, either the Acadia Scout as suggested by Angstrom or the Tsunami SP. I am sure she will be happy with either. And if not either would be a great hand me down to the kids as they grow. Happy paddling.
Let her try a narrow kayak
and see how it feels. I’ve seen new kayakers who have good balance do very well in a narrow kayak. It might save you from upgrading soon.
If you get her a tsunami SP, the kids
will want it.All 3 of my grandsons had little trouble wit it. Two were 6 and one 10 yo.Two girls,7 and 11, absolutely loved it fro the first paddle stroke.
Everything depends on the design
A narrow kayak can be more stable than a wide one. It depends on the hull design.