So I just had this idea. It’s heavily hinted that Garnet changes the course of events in the show whenever she can see an outcome that she likes, visibly doing so to keep Steven safe. And many people have then theorized from this that Rose and Garnet planned out Steven as a tactical advantage against homeworld, because his half human abilities are unpredictable for homeworld.
But I noticed two things while watching the show. One, that, very obviously, Garnet loves Steven more than most everything. She’s undeniably one of the best mothers to him, being more caring about his feelings and wellbeing than the other gems are at times even.
And two, that while Amethyst and Pearl have shown grief over the loss of Rose Quartz, even to the extent of having full episodes about them coping with the loss, Garnet has never had one of these episodes.
Notably, I cannot think of a single time she’s lashed out at Steven over replacing Rose on the team, or really showed any sort of remorse over Rose’s death.
My headcanon, to be quite honest, is that the first time Rose saw that Greg stopped by the temple, Garnet saw the outcome of Steven, somewhere down the line, and steered Greg and Rose in a direction that led to that outcome. Without telling Rose.
I know it’s way off base, but even considering the episodes with flashbacks, Garnet gives him advice that would lead him to forming a healthy relationship with Rose. If anyone would know what could bring them together, it would be Garnet.
Garnet really does love Steven. She loves Steven almost to a fault. I’m assuming that seeing the possibility of a world with him, and not having that outcome, especially with Sapphire’s tendencies to focus on the future as if it’s already happened, would be unthinkable for her. Probably not to the point of forcing Rose towards death, but guiding her towards the idea of bringing that life into the world.