Paris to Venice overnight train with my wife.
 

I'm traveling this August on an overnight train from Paris to Venice as part of my honeymoon. Specifically the Artesia line. We both have France-Italy Saver Passes and I've been using RailEurope. I would like to share a cabin with my wife during this time. I'm certain that if we reserve a double cabin we can share it together. However is it possible to reserve a T3, T4, or T6 cabin and share this with with my wife? Any help would be greatly appreciated. Thanks!

In a couchette, you will be with other people as well (3, 4 or 6 in a cabin).

For your honeymoon, I'd think you would want a private cabin if you can afford it.

I know the number of berths in each type of cabin. And ideally I would like a double. But it is a trade off which we are both willing to consider for one night.

So your question is can & and your wife be in the same co-ed couchette together? I'm pretty sure the answer to that is, yes.

Yes, couchette cabins are coed.

If you share a sleeper compartment (a T3), you share with people of the same sex so you would share with other men, and your wife would be in another compartment with other women. If you want to be together in a sleeping compartment, you'll need to book a two-berth (which is actually a T3 with one bunk folded away).
Couchettes (T4 and T6) are simpler accommodation and are not segregated though these trains, I believe, have some ladies-only couchette compartments. The bunks have a pillow, blanket and sheet, but you sleep in your day clothes, and could be sharing with men, women or children.

Obviously if I knew a couchette was co-ed then I wouldn't have posted this question. Thanks for the information and responses Seamus and GeoffHamer. I ended up booking a double yesterday.

Sorry, Superpage, I did not to be unhelpful. If you asked "are couchette cabins co-ed?" I would have understood better the question.