Lilith was said to have been the first mate to Adam, created by God from the dust of the earth, just as Adam. Because of this, she saw herself as his equal, Adam failed to see things the same way. After years of struggling between each other Lilith put and end to their marriage by refusing to submit to him and fleeing the Garden of Eden. Lilith came to live by the sea where God had previously cast down 199 angels that had gone against his commands, namely having relations with mortal females; thus fathering the Nephilim. The Nephilim have left in their wake a broad imprint in ancient documents, to include the modern day Bible. Known to have been giants that possessed unnatural abilities and knowledge, the Nephilim would later be tagged as Gods, and vampires.
Adam, after having calmed from their their argument began to realize that Lilith would not be returning to him. He shouted to God above him, “What am I to do now, I have no mate!” God looked down to Adam and pitied him. God then sent Gabriel with a handful of other Angels to retrieve Lilith and return her to Adam. When She refused, she was offered and ultimatum. In order to remain a free woman, Lilith would have to watch 100 of her children die every day. She accepted the ultimatum, but added terms of her own. For any male child born she would have dominion over him for 8 days, for every female, 20 days. Gabriel accepted her terms upon consulting with God and left Lilith standing in the center of the sea. God once again took pity on Adam and caused him to fall into a deep sleep when he would remove a rib and form Eve, his second mate.
By this point, Lilith had certainly established herself as the mother of demons, as noted in both the Book of Enoch and the Alphabet of Ben Sirach. Lilith, as a unique creation of God possessed certain attributes that her descendant did not. Having mated the downcast Angels, also unique creations that had retained their immortal lives and unnatural abilities, Lilith was certainly the mother of a superior race of beings. Inclinations of both Lilith and her offspring being known as blood drinkers exist in many ancient documents. Lilith was said to feed on infants. The Nephilim that she bore have also earned the reputations of being blood thirsty Gods.
Though the stories of Lilith and the Nephilim predate the Egyptian empire, many forms of documentation have been found in temple ruins where ancient Egypt once stood. Amulets, statues, jewelry, text and paintings all depict Lilith as a bloodthirsty and vengeful God. So, with all of this information in mind, does one form the opinion that Lilith could be the originator of the Vampire blood line. I caution you to ponder the legend and not form your final opinion until having read all of the theories of creation, as all of them have very valid roots and many forms of documentation that remains until this day.