I have a theory for this: Canon facts are, that she was “devoured” by Ganon (which is why she pops out of the giant malice boar at the end) and Ganon in turn was hiding in that cocoon in the Sanctum.
Since the cocoon thing has some interesting design parallels to the Shrine of Resurrection, I’m fairly sure that it is his homemade DIY version of a resurrection chamber with which he tried to build himself a new body. Link didn’t age in the “original” SoR, so it would make sense that Zelda (inside of Ganon inside the knockoff SoR) didn’t age either.
I have a theory for this: Canon facts are, that she was “devoured” by Ganon (which is why she pops out of the giant malice boar at the end) and Ganon in turn was hiding in that cocoon in the Sanctum.
Since the cocoon thing has some interesting design parallels to the Shrine of Resurrection, I’m fairly sure that it is his homemade DIY version of a resurrection chamber with which he tried to build himself a new body. Link didn’t age in the “original” SoR, so it would make sense that Zelda (inside of Ganon inside the knockoff SoR) didn’t age either.