I recently finished all of Toaru Majutsu no Index, and have started watching Toaru Kagaku no Railgun. I'm currently in the second season of Railgun S, where we get more detail about the Sisters project than the first season of Index gave us.
It is shown that Misaka hands over her DNA map to a scientist at a young age because she believe that it will be used to help cure muscular dystrophy. She looks very young here, appearing to be younger than Last Order/20001, placing her pretty firmly in grade school.
Throughout the series, it is repeatedly said that Misaka is someone who got to level 5 through her own hard work, and started out as a level 1 just like many other students in Academy city. Logically, that would mean her ascent to fame and power is a somewhat recent phenomenon, and that she isn't genetically predisposed to become a strong esper.
Thus, the question I have is why the scientists wanted to use her DNA map for the Sisters project, when she should've been decidedly average at a young age, and nothing exemplary like she is during the anime. Surely there would have been better options, like cloning Accelerator himself?
I haven't read the novels, so maybe I was hoping that someone with more in-depth knowledge of the Toaru universe could fill me in.