Would a hornady 90 gr. HPXT work as a 9mm round with accuracy? My thought is the lighter round would produce less recoil in the SW Lady Smith. Concern if OAL can be acheived using this round as a 9mm and feed correctly into the SW? This is my wife's preferred carry weapon.

Any thoughts on load?

That is my "accuracy" round out of my Glock 26, recoil is light, very fast follow-up target aquisition.

Sure, you can safely drive the 90-100gr JHP to 1400fps in the 9mm W/ very light recoil. For a SD round, I like the 102grRem.GS @ 1400fps. Not my choice for a 9mm, but it would certainly work. Even bettr would probably be a Barnes 80grXPB would likely give better penetration.