I have a sneaking suspicion that Sakura's 'fainting spells' from the beginning of the series are going to come back in. Either as Sakura's pregnant (and that Shizune's mention of it happening since her childhood is a red herring) or as the reason she can't have children.
And as far as raising a child that isn't hers, there's no reason to masquerade as a Sasuke's wife even if she chose to raise his test tube baby. Sakura dusting a house full of Uchiha crap and wearing his clan symbol on his back — if Sarada is not hers and the marriage was never truly a marriage, just an arrangement of convenience for Sasuke — really paints Sakura in a stalkerish light. And she's simply not that way.
I don't see her as degrading herself so as to end her career to take care of Sasuke's illegitimate child, pretend she's his wife, and raise his child as hers while he leaves the village forever. Sakura's kind, but she's not crazy.
We'll see in the next two chapters what is real and what has been the red herring.
And if Kishimoto has Sakura turn out to be this way — stalkerish and giving everything up for Sasuke — then the whole Gaiden has been a red herring centered around Sakura's development, kindness and strength. When all along Kishimoto knew he was just going to leave her out in the cold again.
Those are my thoughts on this whole series: either the Gaiden is going to turn out to be Kishimoto's apology to Sakura fans, or the Gaiden is going to be one more chance for Kishimoto to make Sakura the scapegoat for everything that's wrong with this manga.