Your wife will love the shorter cranks!! My wife rides 130's at an inseam of 30.5 inches due to a knee injury. You'll probably be faster because it will reduce the dead spot in her pedal stroke as she comes over the top.

One other note, we had to raise her seat height to maintain the same amount of extension. She has a better sight line for looking forward now and our seats are set an approximately even height. She's 5'8 ish and I'm right at 6 foot with 170's and a 34.5 inseam. I do think that you'll probably notice when she shifts her body weight a little more now, but the positive trade off is that she'll pedal more smoothly.

I'll be interested to hear how you both adapt to the new cranks.