Officially, no; you need a racial trait such as Elf Blood or the human subtype. Fetchlings (and other native outsiders) are half-human-flavored, but aren't officially human.
That said, there is a precedent. Consider working with your GM to develop a fetchling equivalent of the aasimar alternate racial trait Scion of Humanity.
Native Outsider: Fetchlings are outsiders with the native subtype.
The human heritage is so distant that they are no longer human. To be human you need the (human) subtype or something like elf-blooded or orc-blooded racial trait