No. This is an example of a legendary progenitor myth which was very widespread across the early and high middle ages, but is rooted entirely in the imagination of medieval Europeans. While these stories are largely forgotten today, every Western European nation produced these kinds of historic and genealogies across the middle ages. Oftentimes these stories overlapped or contradicted each other in interesting ways. In the specific case of Ireland, Tea Tephi was a "competitor" of another imaginary Egyptian princess named Scota, said to be the ancestor and namesake of the Scots and Irish.

Medieval historians blended indigenous and sometimes pre-Christian folklore with Biblical and classical narratives to link the legendary ancestries of their kings with more widely-acknowledged heroes such as Aeneas or Noah. Particularly common were attempts to link European nations or dynasties to Noah's son Japheth, as well as the 12 Tribes of Israel.

In Andrew Tobolowsky's recent book The Myth of the Twelve Tribes of Israel, he argued that participating in this shared classical and Biblical tradition of descent was a means for more obscure medieval cultures and dynasties to impress their established neighbors. For instance, Slavic peoples made no contribution to the records of ancient history. But individual Slavic monarchs or historians could insert their ancestors in the accepted body of classical history by claiming that local heroes like Lech and Czech and Rus, whom outsiders had not heard of, were in turn descended from accepted popular heroes like Japheth and Noah and therefore had a legitimate place in the politics of the medieval world.