Thanks for your responses. I’ve been at both Bikes@Vienna and Mount Airey in the past and haven’t seen any adult non-recumbent trikes at either, but I’ll give them a call and see if that has changed.
You are looking for a delta trike (as opposed to a tadpole, which has two wheels in front and one in back). Most (though not all) deltas are upright. Look at something like a Sun X3 or Greenspeed Anura.
Bikes@vienna has definitely had some in there when I’ve been in, though its been a while. I think they even rent them.
Recumbent tadpoles are definitely more popular. Has your wife tried one? They are pretty comfy.
My wife has tried recumbent trikes. In fact, we have a recumbent tandem bike that doesn’t get ridden much. She doesn’t like riding with her legs out in front of her. I’d rather get her onto something like one of the Sun recumbent trikes because they have a wide gear range for our hilly neighborhood, and because they’re harder to flip, but she’s not interested. She wants something that’s like a regular bike with two wheels in the back. They’re available online, but she (rightly) wants to try one before buying.