Divedoggie:
I am preaching the value of Nitrox, but I think she needs to hear it from nuetral sources! Anyone want to help me out? Scientific reasons. Feel good reasons. Etc... :cwmddd:
Having a similar issue earlier, the key ones I found important to her were,
1) more energy after doing multiple dives. On dive vacations instead of sleeping or resting most of the day after the dives, we did sightseeing or shopping. Or in the case of our liveaboard trip, she was too tired to do dives 4&5 and missed out on some cool adventures.
2) She was not much interested in the staying down longer, as she gets cold no matter how warm the water is. However, she really appreciated the safety margin if we dove an 21% profile with 32-34%.
3) Since I do nitrox, and she likes to stick to me like glue, when her time was up,she could not stay with me, so I had to finish early, go back with her and possibly miss something, or drop her off at the anchor line the swim back. When she missed the close encounter ~6' away with a humpback whale because she caught out 3 minutes earlier that finally convinced her.
4) though absolutely no science to back this up, I think she is warmer now. My guess is that she has poor circulation to start and that having the higher 02 slows the cold hand syndrome down. But that is just a guess.
And just last week after hearing from several other ladies how much warmer they are using rebreathers, she has indicated she would like to try that. Rebreathers require nitrox training.
Most people fear the unknown. I would suggest that you allow her to acclimate to the idea herself, let her read your nitrox manual and encourage her questions. Demonstrate your desire to learn all there is and not just trust a single person or book. There is lots of data out there, the more you know, the more she'll trust you. Above all, never at any time, give her the impression she is dumb or is asking dumb questions. Let her warm up to the idea at her own speed, don't push.