Just checked - the name on the file was, "SANJOG, Iyer."
So, not his sister (who I think the mom said was named "Shanti," or something like that. You know, at first, I thought it was Mohinder's child-self as well, but it seems that it's someone his father was studying because of some sort of dream!power. At least that's what the articles in the file seem to hint about.