How do I open a shared Pages doc in iOS?

I'm sick of of the iOS app "Out of Milk". It never synchronizes correctly, so my wife and I always have different lists. I want better solution.

I know - we'll use iWork on iCloud. My wife and I both have Apple IDs and iCloud. She created a Pages doc. She can see it in her iCloud (in web browser) and in her iOS Pages app. She shared the doc with me. I can see it in my iCloud (in web browser) - there is button there that says "View documents others have shared with you". But...I can't see it in my iOS Pages app. In iOS Pages app, there is no way to "view docs others have shared with you". At least, I can't find it.

How can I see this Pages doc (shared with me) in iOS Pages?

Or, how do you recommend my wife and I have a shared, co-editable, synchronized shopping list?