AU Sarah Miller (TLOU)

she gets shot while the infection spread (canon), loses consciousness, appears to be dead. Immediately after, Tommy has to force Joel to keep going so they don't get killed by more Infected incoming (this has to happen because otherwise I KNOW they'd bury her OR figure out she's still alive)

they don't know, but like 4 seconds later more military arrive and shoot the infected left. A medic checks her (she's breathing again, for a moment there she stopped) and decides to rescue her, now that things are "calmer" on their side of the city and they have the equipment

she's saved. Hospital. No memory of that night. She's told she was completely alone in the field. Doesn't remember where her father is. She's told they saw him run. Lots of emotions.

Evil Guy from Fedra is recruiting, there's still chaos outside, confirms to her that Joel abandoned her. She's manipulated and her feelings are a mess even after she remembers nearly everything, and hey, it does look like she got shot and they ditched her, and between this evil voice whispering in her ear, feeling abandoned, scared, and fueled by all the pain, she falls for it fully.

more brainwashing/training happens. Loneliness issues, chronic sickness issues. she HATES Joel and Tommy by the time she's become a FEDRA agent. Changes her last name to Austin, the place where she was found and saved. Just so we are clear, memories are prone to change even in the real world, and in this case between the trauma-induced loss of them, what she's been told by several people, what she thinks she remembers and so on, Sarah fully believes Joel and Tommy left her on purpose and that it's a believable fact, especially adding the things she'll learn about her father's crimes growing up in this world. 

few years later she sees too much crap happening under fedra's control too, she calls it out, gets almost killed, kills people, is fired/leaves, joins the Fireflies. Evil Guy from Fedra is dead, hence why he doesn't get a name. Learns a lot more about Joel Miller the Smuggler, decides not to go see him (because she doesn't want to give him that much thought, he doesn't deserve it)

leaves the Fireflies too, kinda on good terms. KINDA. She's too violent and wants to lead too much to be a team player. Creates her own group of criminals/rebels to control. They kill everybody who seems to be an enemy, including Fedra, Scars, other criminals. Trusts no one to stay. Trusts no one to have her back. Her group actually loves/fears her.

she gets pregnant, she vows to be a better parent than Joel and never abandon her child, Jackie. She gets even angrier but also more hurt. Jackie's dad tries to use the baby to force Sarah to give him control of the group, Sarah kills him on the spot. Brutally (head on a spike later type of warning).

Jackie (Jaqueline) is a random name, she doesn't want any connection with her past. Jackie is 2yo by the time season 1 ends.

won't easily trust Joel, Tommy, depending on the thread she'll hear about Ellie and be curious to see who is this girl he's protecting in the way he didn't protect her.

They are raiders, basically, even if she does her best to keep her child safe, so they camp wherever (with actually lots of comfy stuff and supplies) and can go anywhere