My Missus is Scared of most things TBH;
-All insects or reptiles
-Dogs (any dog)
-Large bodies of water
-Speed in general
-Weather (although she's also fascinated by the weather, so long as she's indoors)
-Cuts, Grazes injuries in general.
-Pesto (No Really)
That's just off the top of my head, there's loads more stuff, pretty much everything stresses her out to some extent.
I think it's more that she's generally not very good at judging the world arround her, so she vears towards caution more and more, it's getting worse especially now we've got kids, and I think she's managed to pass her general perception of danger and risk onto our eldest a bit already.
If one of the kids takes a tumble and skins a knee She really doesn't cope well her reaction only make the situation worse, kids pick up on these things.
She considers me an excessive risk taker, I'm really not...
I used to have a housemate who was scared of fish, she just couldn't look at them even on TV, said they seemed weird and Alien to her.