Story Explanation

Okay so I have always wondered about something: If River and the Doctor were travelling in different time streams, how could Mels have grown up with Amy and Rory, because we know Amy and Rory are definitely on the same time stream as the doctor. Also, we know from Kovarian keeping child River in the orphanage and from the kid being constantly "eaten" by the space suit, that River was trained to kill the doctor when she was a child. This is clearly confirmed when the first thing she does after regenerating (when melody changes actress to Alex Kingston) is poison the doctor. Way before kovarian and the silence come back for her in the library when she's studying archeology. Also, haven't you ever wondered why river is so shocked to see Kovarian in that library. Why she's petrified and shouting "who are you?" At her?

Well. I've sat for ages and attempted to figure it out. So here goes nothing. This is my theory:

River wasn't always on a different time stream as the doctor. Yeah she was taken away by Kovarian at birth, but she was raised on the same time stream, hence mels was able to grow up with Amy and Rory. So, melody (Alex Kingston's melody) tried to kill him the first day she met him. This was before she loved him and before any of their adventures. Hence she doesn't know who "River" is. But, as we know, whatever the doctor whispered in her ear caused her to use up all of her remaining regenerations to bring him back. So, she's done what Kovarian asked, then completely reversed it, found out that she's river and that the doctor loves her all in one very weird day. Also, note that, The Doctor has memories of this River as well, another major indicator that they're not on different time streams yet. At the end of this episode, he gives her the diary.

So then the next appearance (if we actually go in order) was the night he picked her up to take her to see the sky that had so many stars at night that it looked like day light. He explains that the book is for their adventures, that they're travelling in different time streams so she's to record her adventures so that they can coordinate themselves. At which point river states that shes in the highest security prison of all, what adventures could she possibly have. So, this is her first night in stormcage, with this information, we can conclude that she's already killed the doctor (technically, she's done it twice). Major indicator that something very weird happened to her timeline following "lets kill Hitler". Right, time to use your brains, because this is where it gets complicated.

We all know that the moment Kovarian and the Silence return to Kidnap River is after the episode "lets kill Hitler." We also know that River is extremely shocked to see Kovarian at this point. Also, we know she's in stormcage for murdering the doctor (thanks to a very handy minisode). So, we know that by the time Kovarian returns to get River, she's already killed the Doctor (like twice). So, clearly Kovarian has something else she wants to do.

So the theory behind the strange return of Kovarian to kidnap River this second time is that she was only taken so that Kovarian could reverse her timeline. Which I guess you can understand. Kovarian wanted the doctor dead, but River had killed him twice, and Twice he'd managed to miraculously return from the dead. But this is super confusing, because, river who's in the library at uni, only recalls killing him once. She doesn't know she's killed him again in Utah.

So the night Kovarian goes to the uni to kidnap river and reverse her timeline happens between "lets kill hitler" and the "night and the doctor" minisodes. Kovarian reverses rivers time line. So she's effectively about turned and sent back from where she came. Hence there are two Rivers on the beach in utah. Thats not a past river and a future river. Doctor who isn't that simple. Thats the past river, from the original timeline, who'd travelling in the same way as the doctor (this is the river that shoots him) and the one watching is the future river, travelling backwards, opposite to the doctor, who can't remember killing the doctor because her memories of her previous time line are few and far between. Which is obvious: 1. The doctor says he invited the future-new-time line her so that she'd know she's was forgiven and that that version of herself was serving time for a murder she probably can't even remember, his murder. 2. She says "how can I be there" clearly confused as to why a future version of herself would be standing there, knowing whats about to happen and not stopping it, she doesn't know that the other her is now travelling backwards and doesn't remember killing the doctor at all.

But of course we know, the event in utah happens twice. Two different verions of reality, happening in the same instant. The one where River drains her weapons system without killing him, that rips time apart, causes her to remember everything about the other timeline. This is proven in the pyramid when the river that is on the new time line won't let the doctor touch her because she knows that, as they are opposite polls of the (explosion?) that him touching her will take them back to the lake side and she'll be killing him. So, the river that shoots him in the version where he does die is the river on the timeline the same as the doctor. And the river that shoots him in the version where they end up in ciaro is the new river, after she's had her timeline reversed and is travelling back along her own timeline, clearly now in a different dorection to the doctor. I really hope that made sense.

It is after this point where they have the rest of their adventures, including the pandorica's box/the big bang and the crash of the byzantium etc etc. It is why that river in the episodes leading up to "lets kill Hitler" know's exactly who the docotor is to her, but the river in lets kill hitler up to when kovarian kidnaps her to mess up her timeline, actually doesn't know who who he is to her.

I really hope that made sense... It made sense in my head haha. So that is just my theory on the story of River Song/Melody Pond. Yay. Hope its at least close to being right...