I will point out that my husband is lukewarm on swimming, could care less about beaches, but loves to dive. Once he's underwater with his camera, all is good.
Swimming on the surface bothers him. He does it, but does not like it. So even diehard divers have issues.
The gear is heavy -- use a dolly to get to the beach.
The gear is expensive -- rent or borrrow good BCs, regs and wetsuits. Get a good mask, snorkel, fins and boots. Save for a good set of regs and a basic computer. Henderson hyperstretch suits are expensive, but easy to get on.
Lakes and quarrys are cold -- add a lycra skin or pantyhose and synthetic top first.
Dive boats are expensive -- shore dives and spring dives are not. Air fills are resonable.
Fear of water / creatures / drowning -- can't help you there.
The learning curve -- good instructors will take their time teaching the basics. If you can drive a car, you can dive. And it's safer in the water than on the way to the beach -- fewer idiots out to ruin your day!
One more option -- does she have a friend who might like to try scuba classes with her? That might take the pressure off trying to please you, instead of concentrating on her own enjoyment of a new sport.