I have a full size M&P9 that ejects everything about 4 to 8 feet to the right and slightly rear. 4 ft for light and 8' for hotter handloads. I have seen the posts about brass coming straight back but have not experienced it in 4000 or so rounds. My M&P 40 throws the brass same as the 9 and is approaching 2000 rounds.
The M&P will be easier for your wife to operate the slide than an XD service model. In my opinion the grip adjustment is a plus also.
Accuracy has been about equal to the XD. With 124gr. Zero bullets and 4.7gr. VV N340 yields sub 3/4 inch groups at 15 yards over sand bags.
That is as good as I can do with any of them.
I filed the rear sight flat and removed the front sight dimple then re blued both. I then painted the front Orange.
The rear standard sight reflects sunlight different as the day progresses. Related to the rounded surfaces. My old eyes are fooled into aiming higher or lower based on reflection angle.
My grandson with good eyes had the same problem.
The filing has corrected the glare such that I now shoot same elevation morning or afternoon.
Good luck with whatever you get.