In Avengers Endgame, after reaching Morag in 2014, Nebula and Rhodes have this conversation:
Nebula: We're not the only ones in 2014 looking for the stones.
Rhodes: Wait, what? Who else is looking for the stones?
Nebula: My father, my sister and me.
All other stones that they target to get is free of Thanos' direct involvement. In 2014, Thanos is only looking for the Power Stone. The equivalent of going to Morag in 2014 to get the Power Stone is going to Vormir in 2018 to the Soul Stone.
Gamora: Father has found an Infinity Stone. On a planet called Morag.
Thanos finds the location of the stone first. He is in the vicinity of Morag. Only after that does he find out about the 2023 Nebula on Morag. Nebula remembers looking for the stone in 2014 in Morag. In the original timeline Quill gets to it before them. Which is fine. But Nebula already knows of the threat that Thanos was looking for the stone in Morag in 2014. So going there even 6 months earlier would have been safer.
Well, if Nebula knew from her own past of the the threat of getting to Morag in 2014, because she, along with her sister and Thanos were in the vicinity of Morag looking for the power stone then.
QUESTION: Why didn't she warn the team about the fact that Thanos was in the vicinity of Morag in 2014?
If she had, they might have gone there maybe a little earlier, when Thanos wasn't there. No one knew about Thanos but Nebula, why didn't she warn everyone about the obvious risk of running into Thanos in 2014 in Morag?