There are arguments about the origin of beautiful Queen Nefertiti. Etymology of the name is derived from feminine deity celebration and it belongs to known Egyptian family names. Anelder theory says that Nefertiti was a Mitanni princess Gilukhepa, who changed her name to Nefertiti ("The beauty has come") after coming in Egypt. The Mitanni Kingdom was situated between the Euphrates and Tigris River in Upper Mesopotamia. The newer theory says that Nefertiti came from a powerful clerical family, which was close to the court of Amenhotep III.
The name Nefertiti became a synonym for beauty. Without regard to her origin she is still famous thanks to her beautiful face and unusually gentle features, which contrasted with features of her husband. There isn't much information how she became the wife of Amenhotep IV and Egyptian Queen. According to reliefs fragments we can say for sure that she played a significant role in god Aten cult.
Nefertiti as a mother
Nefertiti was depicted on reliefs standing behind her husband Akhenaten with her eldest daughter Meritaten and holding sistrum in her hands - a sacred symbol of goddess Hathor.
Probably other two daughters were born to the royal pair still in Thebes (Waset) - Meketaten and Ankhesenpaaten. Princess Ankhesenpaaten was likely born just before leaving Thebes (Waset), because she is depicted only three times on reliefs.
The royal pair moved to Akhetaten, a new founded capital, around fifth or sixth years of the reign. There were princesses Neferneferuaten Tasherit, Neferneferure and Meketaten born, but some of them died at children's age.
Nefertiti as a royal wife
The share of Nefertiti in Akhenaten's reign is a big question. There aren't any mentions about Nefertiti in diplomatic correspondence, but the mother of the king is mentioned there - the Queen Tiye. The power of Nefertiti likely was in decline after moving to Akhetaten and her eldest daughter Meritaten was depicted more often in reliefs.
The royal family is depicted together for the last time in the 12th year of Akhenaten's reign. THen the second born princess Meketaten died and afterwards mother of the king Tiye and three youngest daughters disappeared from the relief decoration. It is supposed that there were several deaths in the ruler's family and it could weakened the cult of Aten.
Princess Meritaten was depicted accompanied by a male person since the 15th year of Akhenaten's rule. The man was probably her husband Smenkhkare, who became a Pharaoh later. Smenkhkare likely ruled together with Akhenaten for some time.
We don't know much about last years of Queen Nefertiti. Her titles are associated with grandchildren - princess Meritaten gave birth to a daughter and daughter Ankhesenpaaten Tasherit was born to princess Ankhesenpaaten (wife of later Pharaoh Tutankhamun). We don't know for sure when Nefertiti died - there are only questionable evidences that she lived several years longer than her husband and died in first years of Tutankhamun's reign.