That’s so–HEAD CANON ACCEPTED!
“By the time the light from some stars gets here, they are already dead. For those stars, we see only their ghosts. We see their light, but their bodies perished long, long ago.” – William Herschel
All starlight is from millennia and eons long past. If her version of the Sharingan–warped by the Nara’s penchant for the shadows–can actually see ghosts, then she probably finds stargazing comforting. Everyone can see these ghosts, she is not alone in this.
(I actually wasn’t sure whether or not Sarada should exist as well but considering Shikako has displaced Sakura on Team Seven, there wouldn’t even be that smidgeon of a relationship between Sakura and Sasuke that would lead to canon Sarada.
I mean, unless there’s some kind of Uchiha repopulation program going on and Sakura volunteers because she wants a child but understands that it’s not a romantic entanglement with Sasuke? So Sarada might still exist somehow… or a Sakura-Sasuke child named Sarada, not specifically the canon iteration of Sarada.
But DoS Sakura is a lot different than canon Sakura, she’ll probably find and fall in love with someone else entirely and, if she wants, start a family with them instead of having a platonic child with her childhood crush.)
edit: check out Walking Around (Like Regular People) for more Sakako Uchiha