Don't get too hung up on pant size if you never get to the size you 'want'. Not only do brands vary a lot in sizing between one another (even within the same brand it can vary wildly) but everyone's body is shaped differently. I have a friend who's in decent shape, does triathlons and marathons, but she'll never be a really small size just because she has quite a wide frame. So she looks narrow from the side, but head on she is wider than 'average' not due to fat or anything, just due to her build. I also have a friend that has to wear a size larger pants than she actually needs in the waist, because it's hard to find jeans long enough for her legs in her actual size.
Good job to you and your wife on all the exercise!