Munni/Pragya Mystery

I am beginning to believe that Munni has to be different from Pragya. Because, if she lost her memory, then how come overnight her accent, language and behavior changed so much. She may have forgotten somethings that she knew before, but she possibly could not have acquired anything new so quickly! So if CV's want to makes sense of all this, they have to either show that Munni is just pretending but actually is Pragya with no memory loss, or Munni is totally different person who resembles Pragya but not really her. She could not possibly have been Pragya's judwa behen either.