Unfortunately it is too late in the game for any sort of Genjutsu Sakura could have to be of any use. The fact that I believe it was mentioned by Kakashi early in part 2 even that Sakura was a Genjutsu type, and that it could enable her to surpass Tsunade (combined with the strength and medical justsu) shows that even coming into part 2 Kishi was planning on using that to grow Sakura's character, and he completely lost sight of it (and Sakura's place in the naru-verse, sadly, for that matter). If he were to suddenly pull that out, one it would make no sense continuity wise (as Tsunade, under whom she a has received most her tutelage for the past few years, has not been seen to use genjutsu - correct me if I'm wrong, but the only time recall occurred only in the anime), and two Kishi has inflated the sharingan to the point that no other Genjutsu could compare. Not only is Sakura to be fighting alongside Sasuke now (with EMS to boot), making her usage of genjutsu unnecessary, but both the bad guys to be taken down have Rinnegan and some Sharingan (plus what kind of typical - even strong but not sharingan level - genjutsu going to do against the tentails?).
