Ms. TStick and I went to the LGS and first looked at wheel guns; which were quickly and summarily dismissed. I then had a line-up of proven reliable autos made available to her; which let to lots and lots of holding, weighing, aiming, and meh comments - but then something happened - she stopped when she got to the XDsc and her face lit up. She said it felt like an absolute extension of her hand an she refused to put it down. From that time on all other guns were picked up with her other hand, and then the XD may or may not have been moved to her weak side hand while further evaluation took place, but the XD never touched the counter again once she held it.
I really wanted her to like the M&P, and I almost mouthed off -especially when she asked what I thought; but to avoid becoming a husband buys gun for wife story, I just said "Your gun, your choice - any of them here will go bang every time so pick what you want." We then left with the XD.
It has worked well. She looks forward to shooting it every chance she gets, sometimes she will take it out just to look at it, and she scares me with her accuracy now.