Last I checked Abydos and Nekhen were in the South of Egypt. Not to mention Wadi Kubbaniya, Nabta Playa and Wadi Halfa (Arkin 8), which are all important pre Egyptian sites along the Nile.

So if that is indeed incorrect then please point it out to me.

And what kingdoms to the south sent their daughters to be married to Egypt for political purposes? It would be nice to give names of the people and kingdoms that did so, as I don't recall any ever being mentioned. In fact, the only reason such women are called "Nubian" is because they are depicted as dark brown or black. Note how such black images don't occur after the beginning of the 11th and 18th dynasty. It is symbolic of renewal at the beginning of the dynasty and occurs no more afterwards. Therefore, birthing new kings seems to be the point as that is the whole significance of the term renewal of the line. I don't think that many of these queens are actually "Nubian" in any sense, because supposedly the early 11th dynasty was at war with "Nubia". Also, there sure seemed to be a lot of women in this dynasty that were painted with that complexion.

Keep in mind that there was never a single unified entity called "Nubia" to begin with. Kush was one kingdom to the South of Egypt, but there were others as well.

The problem with the 11th dynasty is that there are so many contending theories about the line of kings. It is also odd that all of the tombs and artifacts found have not been published. I would love to see any documentation on the tomb of Queen Tem from Deir El-Bahri.