The chances of her seeing a shark are remote. Chances of seeing barracuda are excellent.
"Baracuda can be a rather nasty opponent if you are spear fishing, have shiny objects or smell of dead fish."
That's simply not true. I always wear a very shiny sliver pendant, It does not attact barracuda, the smell of dead fish has no affect on them either. If you are spearfishing they will sometimes (rarely) go after your fish, but never after you. The best way to avoid even that is to be aware of your surroundings and if you see barracuda following, simply turn and swim directly toward it. It will turn and swim away. Barracuda will rarely let you get closer than about 3 ft. There is nothing to fear from barracuda unless you are feeding fish, then you could lose a finger when it goes for the fish.
The chances of any shark you see becoming aggressive toward you are slim, but it is possible. Knowing how to react in that unlikely event can reduce your fears. If a shark becomes aggressive, keep an eye on it as you swim underwater back to the boat. Present a confident image. Do not swim quickly, but instead remain calm and graceful. Do not swim with your hands, keep them to your sides or clasped in front of you. This is not the time to be flapping them around. If the shark gets too close, get back to back with your buddy. Growling will often cause the shark to leave. Take off your BC and hold your tank in front of you. If he comes in for a taste, let him bite metal. Exit the water quickly, dropping your BC if necessary. You can always fish it out with a boat hook.
"If it looks dangerous then don't touch it!"
Unfortunately, most of the dangerous things we encounter don't look dangerous.
Bristle worms look like furry caterpillars, are nocturnal and have a terrible sting. They have nematocysts all along their bodies that sting. The sting itself isn't particularly painful, but the results can be life threatening.
Once I was taking students on a tour of Davis Reef. I was showing them a spotted moray and was watching the students & moray very carefully, but didn't see the bristle worm. I brushed against it & got a sting on my right forearm. Not a big deal, I continued the tour. When we arrived at the far end of the reef, I noticed a pain under my left arm. Figuring this was not a good sign and knowing I had not trained any of these students myself, I did not know if they would be able to help me if I needed it. I gathered my charges and started toward the boat. About half way back, the pain had moved to the center of my chest and I was having difficulty breathing. I herded everyone back to the boat and climbed out of the water. I took an Actifed and upon reaching shore, I cancelled my participation in the afternoon trip and went to bed. I got up the next evening, having slept until then. A mark remained on my arm for almost a year following the encounter.
I fear bristle worms more than any other sea creature.
Don't touch anything unless 1)you can positively identify it. 2) you know for a fact touching it can't hurt you. 3) you know for a fact touching it can't hurt it.
A good rule to follow is don't touch anything. If it looks dangerous it usually isn't (barracuda). If it looks cute it might be dangerous (bristle worm). If it doesn't appear to fear you, maybe you should fear it (scorpionfish).
A good course will cover all of this and more in greater detail.
One suggestion I'd make is to take the class at home. You don't want to spend your honeymoon studying, you should be having fun! The other reason is you don't want to be rushed to get it all finished in the short time you have, take your time and do it right.
Good luck in your life together.
Walter