YOU ARE BREATHING, AND YOU ARE ALIVE.

We can hear her voice near the end of the film. She tried to encourage Simon to embrace their new home of Eden, even telling him that there is a tree there and that he will like it on Eden. She said, "We have a dream. It'll be just like home." She was trying her best. We can't know why, exactly, they moved to the space station, but we do know that she saved both of their lives leaving Mars and moving to Eden. Had they stayed on that planet, they too would have been raptured away; or maybe they would have become part of the nightmare at the bottom of some other blood ocean on some other terrible moon. Maybe.

I think it is very easy to fall into the trap of judging characters from other time periods and worlds by our own standards, but it leads to analyses that are flat and inaccurate. Yes, Simon was very likely in a cult, and most certainly trained to be a soldier from an early age. But this is not modern life where we have made many strides in lowering childhood mortality rates. This is a brutal world where there is nothing completely recognizable from our own society around to really use as a frame of reference. And, frankly, modern children in our own world are given knives regularly in groups such as the Boy Scouts or clubs that teach them about boating, fishing, hunting, and gardening. We know Eden had soldiers (they are called that in the storyboards that Molly Brown posted on her website), so the knife very likely was specifically for combat, but that is not to say it only had one purpose or was only given to Simon for this reason. 

Nor is there any reason to think that Simon's mother was a bad mother for giving him a knife. If so, then every Boy Scout parent or troop leader is up for worst parent of the year in our own world. And hell, for all we know, the knife was a cherished heirloom. Could it have belonged to a family member like a father, brother, sister, grandfather or the like? Is it so strange to be given something like that? When my mother got to be a certain age, she got a cherished knife from her father after he died. He used it in WWII, and it was well-taken care of. And now I have it, so that is just a thing that can happen even in our world. And it's not unusual to think that it could happen on Eden, too. 

Eden was very likely an agrarian society, or as much of one as could be in the vacuum of space where growing anything was a struggle. Children very likely got practical gifts that some might think of as presents only suitable for adults today–like a knife–but that is us looking at a completely alien society and expecting it to resemble ours. We can't know what life was like for them on Eden–either before or after the Quiet Rapture. We can't know how Simon's mother died. All we can know is that he loves her, believes in her as someone who would protect a precious item, and that he misses her terribly. 

Some of the information we have about her comes from the mad screamings of the blood eel, who is trying to manipulate and control Simon. The things she says can be considered wildly contradictory as well. Quick as a whip she goes from saying that Simon's mother wouldn't even recognize the killer he had become, to asking if death was the only thing she taught him. 

We can guess that she wouldn't recognize the killer he became because she didn't raise him that way. She didn't give him a knife for him to kill with. She probably gave him a knife to protect himself or do regular tasks around Eden. She raised a kind boy, and then society, the Father, the cult, the death of the Last Tree, and Eden falling into extremism (perhaps), stamped a lot of that out of him.

And that last statement from the eel about death has intriguing wording. You can interpret "Was death the only thing she taught you?" a couple of ways:

Simon's mother was instrumental in shaping Simon into the soldier and killer he became on Eden. She put the knife in his hands, and put him on a path to eventually becoming The Butcher. 

OR, when Simon's mother died, her death was instrumental in shaping Simon into the soldier and killer he became on Eden. She put the knife in his hands, then died, leaving him alone to fend for himself in a cold, cruel, baffling world. The death of his mother put him on a path to eventually becoming The Butcher.

The eel is trying to shake Simon to get her way. I think it is very likely that Simon's mother died suddenly, and that her death set him on a path very different from what his mother planned. Her death "taught him" alright. It taught him about cruelty and about unfairness and loss. She herself didn't teach him these things, but her death did. In life, she loved him and protected him. We can't just take what the eel says at face value here, especially when what she says is contradictory.

The last thing I want to touch base on in regards to Simon's mother is that people are attributing lines spoken by Ava in the hallucination scene to Simon's mother. The exchange about the seed pendant that begins with "I don't have it" is a line delivered by Ava.

Right before the SM-13 mission, Simon would have asked his captors for his seed pendant back. Ava says "I don't have it" and then goes on to say that the C.O.I. Council Authority confiscates these seed pendants because they plan on making a garden of their own. Simon then says that the "Last Tree is dead." This makes Ava say, "What?" That fragmented conversation ends with Simon saying that the Last Tree is "Eden's Grave." I am not sure why people think this is his mother's voice when she sounds very different from Ava. But if some of the random hate I see for Simon's mother floating around is because of this dialogue, please reconsider what you are hearing. 

The only clear dialogue we have from Simon's mother is her trying to comfort him when they are forced to leave Mars. Again, we do not know why they left Mars. We do know that Simon disagreed with the decision, making his mother ask him not to be like that. He was probably a headstrong kid. In fact, we know that he was unafraid to stand up to authority because he flat out disagrees with the Father, the religious leader that obviously had a lot of sway on Eden. Simon tells him to stop lying about the stars in a flashback scene (timecode 42:40).

("Stop saying they're gone. We can all see them." Simon has the knife in this flashback. He's kept it all this time.)

What kind of mettle do you have to have as a kid to argue with a religious authority like that? He had gumption. Markiplier has said that he himself runs on "fuck you energy." I think Simon is of a similar stripe. I bet he got it from his mother.

She raised a kid who didn't just go along like a sheep. She raised someone who thinks quickly on his feet, tries to survive, is ready to fight when the chips are down, and who picks everyone else's well-being over his own at the end of it all. 

("Please keep this safe, okay, Mom? It's more than me. It's more than me." Simon praying to his mother to help get the black box data to safety.)

Simon's mother was a good mother who loved him. He loved her, too. That is why he asks her to protect the data. He doesn't believe in the teachings of Eden or their god, but he believes in his mother. Markiplier made a movie with effective and gripping visual storytelling. Not everything is spelled out, but he tells you the big thing you need to know with symbols and gestures and beautiful imagery. Believe what your eyes tell you when watching the movie: Simon cherishes that knife sheath because he cherished his mother.