If you night dive on Bonaire, make sure she knows about the tarpon. A 4 - 5 foot silvery fish rapidly making a pass by you close enough to touch can be a scary experience if you don't know what kind of fish it is.
The term 'shark' is far too broad. Many nurse sharks resting on the bottom look more like some sort of weird catfish than a shark. Many of the 'sharky sharks' people see are reef sharks; imagine a 3 - 5 feet skittish animal passing by and quickly leaving the scene (assuming you're not on a shark feed dive, or where they're conducted) while the guide tries to get the paying customers to see it before it's gone. Hardly caught to bolt.
All of which is far different from the videos you see of people diving with great whites in Guadalupe, Tiger Sharks near Tiger Beach, Oceanic White-tips near Cat Island, Bull Sharks at various places, etc...
If she's worried about seeing a Great White, they're a colder water shark from what I've read. Not something likely in Bonaire.
I've spent 8 1-week dive trips in Bonaire, well over 150 dives there, haven't seen a shark there yet. If I did, I'd expect a nurse shark or reef shark. The guy who does
guided east coast shore diving, Bas Tol, once told me he'd seen a hammerhead shark at some point.
Any idea how she will react to green moray eels & great barracuda? You might see a big version of either.
Richard.