My Nebula theory in Infinity War (POSSIBLE SPOILERS)

So recently Karen Gillan said that Nebula's backstory and past will be explored in even more darker ways in Infinity War. Here's my theory on how her character will play out in Infinity War and what her arc will be:

Last we saw Nebula she was floating away in a space ship given to her by the Guardians for her Thanos Hunt. She flies to Knowhere to buy some extremely dangerous weapons for this hunt. While she is at a Knowhere store checking some weapons out, she sees a knife, one of the kind you see in a dentist's office. She has a flashback and we cut to young Nebula and Gamora fighting. Gamora has the upper hand, and after the fight is over Thanos drags her to a laboratory where he puts her in a circular tube of water, takes the knife Nebula saw and uses that knife to cut off the arm of an unconscious Nebula in the tube. He replaced it with a metal arm. Nebula's eyes were broken between her and Gamora's fight. He sews the broken eyes back together with metal and it's just disturbing. Nebula wakes up from that tube, looks at her metal body with awe and horror, turns to her father with tears and anger in her eyes, and Thanos just puts a finger on his mouth, implying her to not say anything and be what he wants her to be. She looks in the mirror, a Frankenstein type monster created by her own father, with vengeance against her father and sister in her eyes.

Nebula snaps from that flashback, kills the store owner, steals the weapons. She goes outside the store to see everyone running away in fear. She sees the ship of Thanos arriving on the planet as she takes out her two knives, ready for battle. As Thanos comes out of the ship, Nebula launches an assault on him, reminiscent of how Drax launched an assault on Ronan in the same place. She tries to beat Thanos, even slashing his arm a little bit, and he is pissed off. He takes her mechanical hand and crushes in his own hands. Nebula lets out a piercing scream. He throws her inside his spaceship.

Later we see a bond developing between Loki, who has joined Thanos' allies and Nebula, with both of them having similar backgrounds with competitive siblings and daddy issues. Her arc is finished when she saves Gamora from a major blow from Thanos, and gets killed instead. She dies in her sister's arms on the battlefield. Right before dying she says, "You'll always be my sister...".

Also remember how Millie Bobby Brown was on the set of Infinity War? I guess she will play young Nebula in a flashback and they're keeping her role a secret. And I just looked at that photo that Millie/Russo Bros. posted and hmm, there's a purple light flashing over them. Guess she will be playing young Nebula after all.