Would Earth be in the Slow Zone?
Nyjora is claimed as the first human world in the Beyond several times in A Fire Upon the Deep. Further, in A Deepness in the Sky The Qeng Ho are slow zone traders who still remember Earth.
For instance in Chapter 6 of A Fire Upon the Deep:
Ravna had no doubt of his humanity, but all humankind in the Beyond was descended from Nyjoran stock.
when Ravna see a image of Pham and knows that he is of different stock, and in Chapter 8
[...] virtually the opposite of the matriarchy that all Beyonder humanity descended from
when discussing Pham's culture of orgin.
In A Fire Upon the Deep the posters in the UseNet feed discuss the location of Earth in the context of the Death to Vermin/Araphanti Hegemony threats before the attack on Sjandra Kei.
"Where is this 'Earth' that humans claim to descend from? 'On the other side of the galaxy, and deep in the Slow Zone' they reply. Even their proximate origin, Nyjora, is conveniently located in the Slowness."
The depth of Old Earth in the Slow Zone is perhaps the reason for the "Miracle of Nyjora"; that a race buried that deeply could eventually achieve the Beyond.
In the short story "The Blabber", the plot takes place on a human world on the fringe of the Slow Zone. Close enough Beyond residents can visit and some low beyond tech works for a while. This world was colonized by an Earth slowboat by Americans, or at least North Americans. The protagonist refers to Earth being far deeper in the Slow Zone. Story takes place after the 3 Tine novels.