In the Library story, when she checked her diary with Tenant, one of the "meetings" she referenced was the "crash of the Byzantine" (sp?) which is the story currently unfolding.
For River in the Library, that was the past. But presumably for the "current" River she has yet to write that entry.
If you think about it, given that she died in the Library story, she had already lived out her time with the Doctor (whichever one it is, presumably a later one that 11th), so in the Library every meeting and adventure they'd had was recorded, but in the diary at the moment there are still entries yet to be made.
What happened to the diary? Was it left behind on the library planet?
Interestingly though it would suggest that while she has images for all the incarnations of the Doctor, she doesn't necessarily know which order they come in!