I doubt Sakura has that much chakra, and CmDr_RavEn, you are pretty much saying it's because she didn't have any teaching, well, that is true to some extent but that's HER fault, unlike Naruto and Sasuke who WANT to train and get stronger and, especially with Naruto, nag to someone to teach them, she dosen't. So that's her fault she's weak. She has no motivation, and wastes time. And with how weak she is and if she actually some day realizes she should be training like everyone else, doubt she would amount to that much