My suggestion, Twilight out of Dana Wharf. As a deckhand there (yes, I'm back full-time, somewhat to my dismay) I can give some possibly unthought of reasons to try this.

1) It's the shortest trip you can take (4 hours)
2) It's very likely that other guys will have their ladies out also. Many guys use the twilight for what you're thinking. She'll be more comfortable if she's not the only lady out there.
3) These trips do tend to focus more on fun than hardcore fishing.
4) 99% of the current deckhands at the Wharf are good guys, and want the passengers to have fun and catch fish. We all have our bad days, but over all there is many great crews there. We are all a bit weird, but I can't recall too much eyeball stabbing. Though there's probably been other gross acts best left in the mind and not acted upon.
5) After it's all done, you'll both know if she likes it. If she does, be stoked. I sure wish my wife liked to fish. She thinks I'm nuts, she can't fathom (pun intended sorta) liking it, let alone living for it.


Good Luck,
Amish Ed