And that's the thing: I talk with her about everything. She's not a part of the company, but she's incredibly integrated into our workflow. Because she's there with us in everything we do, I think our relationship has actually strengthened — and quite a bit at that. Being able to share this experience with her has been wonderful. She cares deeply about what I do and wants to be a part of it. And I think that's key. Even despite the distance (we spend 9 months out of the year over 3,000 miles apart), we're extremely close and I'm hopeful for our future, notwithstanding the insane hours I put into building the company.
And, above everything else, I think that's important. Don't overlook her; instead, integrate her. There are a lot of great tips in this thread, but I'd say if you take anything away, it's this: allow her to fall in love with entrepreneurship as much as you have. If she truly loves you — and I very much believe this to be true — she'll love what you do as well. That's especially true with us: we're entrepreneurs to our core and with everything we have.
My girlfriend truly believes in what I am doing and my vision for the future. She supports me in everything I do and without her, I'd probably have given up long ago. Her steadfast support keeps me going. The adage "behind every great man is an even greater woman" is so very, very true.