Yes, my wife and I both practice on a regular basis shooting both right and left hand only with our Glocks. My wife is of average height/weight and does not have problems shooting one handed as long as she can get "crush grip" (as taught by Massad Ayoob) and can lock her wrist, elbow and shoulder to get her weight behind the pistol. With that said, my wife is also abnormally strong for a woman and competes in Brazilian Jiu Jitsu and has the requisite upper body strength and many years of practice/competition and world class instruction, too. I am much bigger than she is, but I can get a Glock 17 to stovepipe every round if I hold it loosely in hand with my wrist and elbow bent with no tension so the pistol does not have firm resistance/support in cycling. It is not necessarily technique-- it helps, but sometimes some firearms just aren't a good fit for a particular shooter.
I would ask around and see if you can find a S&W M&P for her to try and see if she likes it and if it works better for her with the same ammo. The market is crazy right now, but if she finds the M&P works better for her, she should be able to trade a Glock for an M&P as the M&P is cheaper when new. My wife and I would be happy to take her shooting if she happens to be near Michigan.
