Cost versus how much it will be used as we have a two yr old she doesn't get to dive as often as she likes
I am someone who dove cold for the longest time, layering up with more and more neoprene, scheduling vacations only when and where it was absolutely warmest, etc. I assumed diving dry would be too expensive, too complicated, and not enough like actually diving. In fact, I almost just quit diving because the overhead associated with it was so cumbersome, and I was still getting too cold, too often.
Thanks to some knowledgeable and caring input by Jim Lapenta here on SB, I very reluctantly got a dry suit a couple of years ago, only because it was the last thing left to try before I gave up on diving. Yes, it cost some, but it has ultimately become the best investment I've ever made in diving. Yes, it was a bit more complicated, but you get the hang of it over time. To my great surprise, it still felt like diving even though I wasn't getting wet any more (not
very wet, anyway
).
I have not been cold once since I started diving dry. This is miraculous for me. Because I am finally and reliably comfortable, I'm enjoying diving more than I have since the very beginning. One way of looking at it for your wife is the less she dives, the more important it is that the dives she does get are as enjoyable as they possibly can be.
As for me, I dive dry all the time now. Don't miss the wet suit at all and honestly, the dry suit is actually less trouble than my massive neoprene collection was. I thought I'd feel self-conscious diving with it in the tropics but I was so busy being comfortable and enjoying myself that I forgot about it.
So there's one person's experience, for what it's worth. Going dry saved diving for me, and I really wish more people with thermal issues would consider it. It rocks.