I am a teacher, now retired and know Bonnie pretty well (we aren't married). You need to decide if you want to encourage her to grow in her own direction or do you want to control her? Controlling Bonnie isn't going to work!
She always let the Glock 26 grip twist in her little hand so it was offset in the web of her hand. She also liked to lift up quickly to see the shot (no follow through). I'd simply say "Watch your grip" or "follow through" then step back and let her fix the problem.
I never corrected her in front of anyone else. I'd whisper to her or speak with her alone. But heck guys, that's just common courtesy.
Women love to interact with each other. If you can bring a female friend with you to the range, let Momma teach what she knows then ask you when she has a question, that works great! Of course, you stay out of it unless you are asked for help.
When Bonnie began to see problems with other people and their shooting, I would listen to her comments and stay the heck out of it. If she was correct, I'd let her teach. I never heard her teach someone incorrectly.
Perhaps these things will help in teaching your lady to shoot.