There are women who ruled Egypt, and maybe one of the first ones is Queen Merneith (also written as Merytneith). She may have been the daughter of Djer, and she may have been the wife of Djet who seems to have died after rather a short rule. This was not unheard of those days - diseases were rampant and military skirmishes common.
She lived such a long time ago that there are not many details about her life. Her exact position is not certain, but we may draw conclusions from the fact that her name seems to have been written in the famous Palermo Stone that states the list of kings of early Egypt. The terminal signs of her name can be seen there. Also many seal impressions and inscribed bowls link her name to those of Djer, Djet and Den.
Also, her name is mentioned in a large stone stela that was found in Umm el-Qaab, Abydos. The stela is now in Cairo Museum. A large stela tells of her importance.
Merneith's name is not written in a serekh as kings' names were at that time, even if she was included in the king list. This may denote she was a regent, ruling for her infant son Den. Her rule as regent would explain Den's long rule - he celebrated two heb-sed jubilees, and this was possible if his rule was counted from the moment his father died.
Her name is mentioned also on a clay seal impression with the names of the early kings from Narmer to Den. Here her title is the "King's Mother". Clearly this traditional title was important already, and thus she had a recognized status.
However, in New Kingdom king lists her name is not mentioned. Perhaps her son Den was considered the real ruler, and a regent was not taken to be a divine ruler, a king.
A detail from the stela of Merneith. The sign on the left reads Mr (or Mer) and means "beloved". On the right is the symbol of the goddess Neith: crossed arrows over a shield. Merneith = Beloved of Neith. Photograph is from Wikimedia Commons.
If the size of her tomb is anything to go by, Queen Merneith may well have ruled Egypt for a while. Her tomb is in Abydos, the famous area of Umm el-Qaab, situated to the west of the tomb of Hor-Aha. The tomb is so big it is fit for a king.
She also had subsidiary burials, just like the kings before her - 41 in all. These were her servants, the objects found in these tombs confirm this.
Many of the seals from her tomb have the name of Den on them. Also seal impressions were found where was the serekh of Djer, and a serekh-like impression with the name of Mer-Neith. The difference between these was that where the serekh has the Horus-hawk on top, Mer-Neith's "serekh" had the Neith-standard on top. The queens of this time seemed to have a strong connection to the warrior goddess Neith, and many of them bore Neith in their name. The name Merneith reads as "Beloved of Neith".
There is an interesting stela fragment at the Louvre Museum with Merneith's name as well. You can see it here.
Her tomb, like most tombs, was plundered in antiquity.
If you are interested in reading more about the tombs at Abydos, there is an interesting article on the subject:
Abydos and the Royal Tombs of the First Dynasty Barry J. KempThe Journal of Egyptian Archaeology Vol. 52, (Dec., 1966) , pp. 13-22Published by: Egypt Exploration SocietyStable URL: http://www.jstor.org/stable/3855814