Ray says:

Hey Mary,

The process of uploading photos is pretty easy.  You log-in to your MyBabyOurBaby account. Then next to your niece's photo there will be a red link that says "Write a Story", from there you'll go to a page that asks if you'd like to Upload Photos for your story.

Hope that helps.  And creating a how-to page is a really good idea.  I'll get on that.