Yes, the introduction of a "Royal factor" into the biography of Tjuyu makes the whole scenario better contextualized. The reconstruction  can stand. About the age of Nefertiti when she got married, if Amenhotep III and Tiye thought for real that she had to be a potential coregent [in case their second son failed], she had to be around 15. This would mean that she was born around 1366 BCE [keeping 1351 BCE as reference for when Amenhotep III - Akhenaten got the crowns]. If we consider the earliest possible date for the birth of Amenhotep III, 1400 BCE, we could have enough time for Prince Thutmose to be adult and have a couple of daughters.