We later learn that her people's first contact with Earth's pre-human civilization of dragons went very, very badly.
In Freefall humanity has made contact with a few alien races, though mostly aliens of the Starfish variety so relations are limited. Also many humans were wary of accidentally causing an interstellar incident when first meeting Florence or Sam (until they realized that Florence wasn't an alien and Sam was annoying). When they found Sam's species, the summary was "keep searching".
Vexxarr falls (ahem) into this situation frequently enough, so when he doesn't see natives...
Sploorfix: Hiding? Vexxarr: From two unarmed alien bags of fluid gastropodding across their local gren space? We should have seen either their military or their nerds by now.
In Loon Land the alien Lana Loon lands on Earth and has a close (failed sexual) encounter with the terrestrial loon Mike Moon [1].
Mike: Hang on! You've got like five holes down here! Which do I poke it in? Lana: All of them.
The prologue establishes that humanity's first contact with aliens was with members of a race called the Orgus, who were fleeing after the Umiak invaded and overtook their homeworld. This also alerted humanity to the war between the Umiak and the Loroi, and the impending danger of Earth being dragged into the conflict.
The main character, Alex Jardin, is the first human to make contact with the Loroi, as they rescue him after the scout ship whose crew he was part of is destroyed by an unknown attacker.