The early concepts of "very strange affairs" were very different from what happened in the end - the SCREENRANT portal writes about this in its material. For example, in previous versions eleven, whose role is fixed for Milli Bobby Brown, was a completely different character. Back in 2017, the authors of the series Matt and Ross Daffera shared in an interview with Vulture, which in a pilot episode eleven there was a negative heroine, which "brutally killed people." By the way, at that time the project was not called "very strange things", but the "montok", while the pilot because of the abundance of cruelty received Rating R.
Later, the Daffera brothers again remembered their initial plans, told that in another version of "very strange cases" the eleven had to die irretrievably, so the series was to be limited to only one season. This did not happen, because manufacturers in the face of Netflix wanted a long history for several seasons. This forced the Duffer brothers to rewrite the script, so that eleven remained among the main actors.
As a result, eleven won great popularity and love among the fans of "very strange affairs." The audience in it bribes her kindness, which was never broken during her stay in the Hawkins laboratory.