In 2014, when the first Gamora and Nebula, which has definitely gone through some rough patches over the years.
Since then, the two daughters of Avengers: Endgame. Tragically, they have never been able to get the timing right on their emotional relationship. The question then has to be asked. Are they true sisters? Are they even true friends?
Attempted Murder
Usually, friends don't try to kill one another. And as Nebula freely its in Avengers: Endgame, the two sisters try to kill each other multiple times. The most prominent instance of this on-screen comes in Guardians of the Galaxy, Vol. 2.
When Gamora is pondering matters on Ego's planet, she hears a faint disturbance. Of course, this turns out to be Nebula, who attempts to crash the ship she is piloting directly into Gamora. It would absolutely kill her and it's a surefire sign that they're not friends.
Careless Second Attempt
As this scene progresses, Nebula ends up requiring Gamora's help. Having fully become a hero and a good person, Gamora swallows her pride and saves Nebula's life.
Instead of stopping the fight from that point on, Nebula keeps fighting and tries to kill Gamora once again. It's one thing to try to kill someone. It's another to keep trying to kill them, even after they have just saved your life.
Nullified Sacrifice
In Avengers: Infinity War, one of the most gutting scenes comes when Thanos throws Gamora off a cliff to obtain the Soul Stone. It's a chilling moment, but there is still a chance for the Avengers and the Guardians to fight to make sure her death was not in vain.
Instead, when they have subdued Thanos, Nebula shows up and reads Thanos' emotions and verbiage. She then reveals to the hot-headed Star-Lord that Thanos killed Gamora. Star-Lord acts as one would expect and the entire death of Gamora was for nothing, as Thanos gets away. Did Nebula really have to say something?
Claiming Insanity
At the climax of the first Guardians film, Gamora manages to get Nebula alone. Granted, she's hanging off a cliff, but it still gives Gamora the opportunity she needs to try to get through to Nebula.
Instead of taking Gamora's hand, Nebula calls her crazy and chops off a part of her cybernetic arm. It's quite a drastic measure to get away from Gamora. Would a friend act in such a manner?
Held Captive
In the second Guardians film, the team is able to procure Nebula, who had been held captive by the Sovereign people. If Gamora and Nebula were friends, Gamora would have released her sister as soon as she got her back.
Instead, the Guardians keep her captive and in handcuffs. She's still a prisoner! They have no trust between them. And it can be hard to have a rock-solid friendship without trust.
Ripened Fruit
Furthermore, while Nebula is held captive by the Guardians, she repeatedly asks for something to eat. Namely, she has her sights set on a piece of fruit that tumbles about the Milano.
Repeatedly, the Guardians tell her that the fruit is not ripe. This proves to be true when she eats it, but that doesn't mean it was not edible. Clearly, Nebula was starving and she needed something to eat. Unripe fruit is better than no fruit at all. But they kept her away from the basic need of a living thing.
Gamora's Ship
Returning to the first Guardians film, there exists another attempt on Gamora's life on the part of Nebula. It is Nebula's doing that Gamora's ship gets destroyed and she winds up floating in space, left for dead.
It is Peter Quill who ventures out to save Gamora, but it's hard to ignore the reason why Gamora was in danger in the first place. Just another instance on the long line of Nebula's attempted murders. A friend would never do it, though.
Past Nebula's Reservations
Over the course of the Marvel films, characters have shown the capacity for change and Nebula is definitely one of them. However, it seems like she will always have streaks of villainy and blood lust within her, no matter what.
The past version of Nebula from 2014 understands the growth that she and her sister encounter over the years. Instead of acknowledging this and doing what she can to better herself, as the 2014 Gamora did, she tries to shoot Gamora once again. Gamora is saved by the present-day Nebula, but it's hard to ignore that the past Nebula still had the desire to kill, in spite of what changes.
Gamora's Departure
Nebula is not the only one who continues to put a rift in the potential for friendship between the two. Sometimes, it is Gamora's fault, too. Take the end of Endgame, for example.
There, Nebula, despite knowing that she has friends in the Guardians and, potentially, in Nebula, decides to leave the battle when Thanos is killed. If she was truly friends with Nebula, she would have stayed behind. Instead, she walks away from her altogether.
Sisterly Bond
It seems pretty clear that Gamora and Nebula are just not very good friends. Between the attempted murders and the constant betrayals, it seems unlikely that a true friendship could ever be forged.
That is because there is something greater at work between the two. Gamora and Nebula may not be friends. But they are sisters. And in the forthcoming third Guardians film, they're going to have a chance to prove it. Even if now is a good time to be skeptical.