Board Thread:Naruto Discussions/@comment-26104757-20150617022803/@comment-5273810-20150629144700

Reason in Universe, Chakra Control wasn't as great as Sakura and Tsunade. Reason outside of Universe(a.k.a. Real World Reason) Shizune can't do it because Sakura needs someone to surpass.

To prove my point, this happened with all the legendary Sanin. Orochimaru trained Anko, she couldn't be as awesome as she could have been because Sasuke needed a bar to be compared to and she just happened to be that. Jiraya trained the 4th Hokage(Naruto's Dad), The 4th Hokage couldn't do certain things because Naruto had to have something to compare to and surpass. And of course Tsunade trained Shizune, Shizune couldn't do that healing jutsu because Sakura needed to have something to surpass.