well, scince no one is repliing, u already know my answer.

maybe she died, but Nefertiti was i guess jealous [as u said above] bcos the lady bore Akhenaten a son, and she did not...or maybe she just died or something..

I think she probably died, but I have serious doubts about the "death in childbirth with Tut" theory.
I have read in more than one source that her name and/or titles have been found on reliefs that also feature the later versions of the Aten's name, implying that she lived until around year 15 or so.

Well I voted for "dead", that's the only thing we can be sure about... But I think she survived Nefertiti; Aldred mentions that she was alive in Year 16 and was depicted with Akhenaten, Meritaten and Ankhesenpaaten (standing behind the two princesses, which shows she was of lesser rank). Nefertiti kind of disappeared after Year 14, it is very likely that she died around that time.