Your signature says you live in Florida, so that makes the introduction to underwater easier!
As stated above, have her snorkel above you at a shallow water site. Visit on the surface, then she has fun topside while you have fun ten feet below.
Got a camera? Take pictures of what you saw, bring her a conch shell, demonstrate superior boyancy control by staying just in reach below the surface while you swim together.
Does your dive flag have a gear ring? Have a cool beverage together, toss scuba toys, relax and take it easy.
So she's not underwater... it's still a swim date.
But do not let her use your scuba gear without proper training.
If she's okay with it, have her watch some Open Water Diver DVDs or sit in on a class. Our local dive shops do training at a community college while others are swimming laps, so it lets others see what it's about in a non-threatening environment.
Any local dive clubs nearby? She may be fine with shore support while you and your buddies dive. Non-diving members can show both of you the range of options for mixing scuba and other activities with less resentment.
And have her check in with the SB crowd, which includes divers and non-divers. If she likes what she reads, she may be ready for the next step.
Meanwhile, she may be fine with getting a tan while you swim with the blue fishes. And that's good, too.