My wife was an atheist when we first started dating. Things were difficult at times, especially since I was also going through my overzealous convert phase. I eventually cooled off, and as time went on and we married she started to slowly shift. She became agnostic, then somewhat deistic, and now she is a full theist but not (yet

) Christian. Now we share a strong belief in God (generally), his active involvement in the world, etc. We religiously get along pretty well, and our biggest difference is pretty much Jesus I suppose.
That said, I think the most important thing was that, religion or not, we shared a similar worldview/morality. We both agreed on most things, and had no problem agreeing to disagree on others. She also became supportive of my faith as I became less pushy about it.
So for advice, I would say a couple things. First, figure out what kind of atheist she is - you seemed to describe her as the indifferent sort. So long as she truly is indifferent, she would be no different than a nominal Christian in practice. In fact, even a nominal Christian could be worse since they may judge your piety as superiority and self righteousness etc. Biggest thing here either way is to leave considerable room for her to breathe and absolutely do not push it on her in any way. That's like relationship 101 stuff, and you probably already know if you've dated a year. If she isn't truly indifferent or tolerant, she most likely will (begin to) oppose your faith, which can take many forms, and it will cause conflict much of the time.
Second, see how much you share in other life views (family, morality, child rearing, politics I guess, etc.). If these are too different, then I imagine the difference in religious belief would exacerbate the tension over them.
That said, if she is a truly selfless and loving person even extreme differences can be bridged with effort. Although, be prepared to live your Orthodoxy alone to a large degree. Even if my wife is supportive of me and my faith, she still doesn't really share in that aspect of my life as much as I may sometimes wish. So while we get along amazingly well and I don't regret marrying her even for a second, that is something I'm willing to live with in case she doesn't ever convert. You will need to be ready to accept that possibility as well, and not hold out expecting an inevitable conversion.
Sorry this was so long and meandering, hopefully it's of some use.