Hey TN_Mike, I'm glad your wife has decided to make the switch. I'm sure once she gets more comfortable with it she will never want to go back to purse carry unless absolutely necessary.
I'll admit that I'm a little biased to behind the hip or kidney carry. I have tried smart carry, ankle carry, shoulder-holster carry.. pretty much everything but thigh carry and while I'm certainly interested in trying that I still end up going back to behind the hip. It just works out the best for concealment, comfort, accessibility, movement, all of it.
Shoulder holster carry can be very comfortable... except I know that you have children (lots of children) and when carrying a child while also carrying a shoulder holster you either end up with a kid playing with the butt of your gun or constantly having to reposition it as you try to get your kid comfortably under your arm.
Since having a child of my own I have carried in a shoulder-holster once and it didn't go so well.
Another reason I love behind the hip carry is because it doesn't interfere with carrying a child. You can see this in my latest video "
Carrying a Gun and a Baby."
You can also watch my holster videos... in one of them I go over cant. Cant helps SOOOO much for comfort and concealability and it does make a HUGE difference as to the speed and ease of draw. Where your gun is on your body and how your firearm is canted in your holster will make a difference to your carrying experience. If the cant is too severe or not enough it can be hard to conceal, hard to draw and uncomfortable to sit with.
I do LOVE my UBG holster as well as my TT IWB or my husband's Milk Sparks VMII. I'm trying out the Galco N3 as well and have yet to come to a conclusion about that one.
As far as comfort is concerned, I've said it before and I'll say it again, the heavier the gun the more support you'll need for comfort. The XD is not a heavy gun but my holsters with two points of contact to the belt spread out over a wider surface area increase the comfort of carry 100 times (especially when you have a kid's leg adding to the weight).
A holster with only one point of contact to the belt or two that are very close together seems to hang on the belt and waistband, dragging it down and causing tension around the waist and leading to discomfort.
Anything directly on the hip at 3:00 (or 9:00 for lefties), strong-side may be difficult to conceal and hard to manage around kids.
Ankle carry can be convenient for freedom around the waist but hard to get to, and you certainly can't draw and move at the same time. But I'd certainly take that over not being armed at all.
I'm not sure what else I can tell you right now. If you have any specific questions, please ask. I love talking holsters!!!!