Haven't you read what Sasuke said She cant do anything at this situation?
If she takes Obitos eye she will look more ugly and it is not like she can master that sharingan in a minute and make use of it in battle even if she does nothings gonna change..
Because Obito is alive?When he awakes I hope to see his Susanoo.I think it'll be gray or maybe butter white? Anyway,Sakura would still be fodder, she couldn't handle the chakra stain, and if she used kamui once she'd die.