I originally started out with a set of Remington passive (non-electronic) muffs with a noise reduction rating in the low 30's. They worked great. For training classes I bought some electronic muffs, first the Peltor brand and next a set of ProEars. The noise reduction ratings were less, somewhere in the low to mid 20's. I finally switched back to the passive Remington's because they were quieter. So while the electronic muffs were great for hearing range commands I like the passive muffs better. Make sure the ones you got for your wife has as high a NRR as possible. Good luck.
best wishes- oldandslow