It's a hypothetical.
Evidence against:The Garenhuld attitude is not cultural. The culture has changed vastly over the centuries, but this has been a consistent and ubiquitous feature to a degree which far exceeds cultural bias. Even the GM has said that it indicates some significant selective pressure. Quite possibly related to the dead guardian and doubly landlocked ring of dead systems. The Garenhulders aren't curious because the curious ones didn't get the chance to have curious babies.
Garenhulders despise innovation in exactly the same way that Earthers despised creative sterility.
The people there were culturally opposed to innovation or advances, making them perfectly stable for what the Exiles needed.
Oddly enough, Saiyans as a society haven't touched this planet. Saiyans as individuals have...and they're the only reason things are as good as they are. When the Saiyans landed, the planet was at the tech equivalent of the High Middle Ages. The people of this planet have a strong cultural aversion to innovation.
The humans of this world have as much martial arts knowledge as you would expect from the Earth of today; averse to innovation or not, a few millenia of military tradition dating back from when rocks were new adds up.
In exchange for a near-total lack of cultural drive to innovation, they have a deep and varied tradition of oral and written legends that encompasses a vast tapestry of stories from the length and breadth of their history, as well as fictional tales from invented worlds aplenty.
An extreme cultural distaste is something that can and does happen.In that particular case, the kids were informed, and happily (for the Exiles) were young enough to be wholly assimilated into saiyan culture by the process of childhood education. They lived their lives as slightly unorthodox saiyans, identifying more with their adopted people than with the Garenhulders they technically were.
Okay, Occam's Razor time.Yes, missed it. It shows a nominal age. One she probably even believes herself. However, she is still described as small, timid, and little-sistery. Especially with underlying Saiyan biology, that could easily cover a gap of a couple of years.
Hypothesis 1: Maya is a mutant human who simply did not develop the cultural aversion to innovations.
Assumptions: Three, two with strong evidence.
Hypothesis 2: Maya is unknowingly of Saiyan descent who is under a Masque, and as such she does not develop the aversion as it is entirely biological.
Assumptions: Four(Saiyan, Masque, Aversion Biological, Saiyans immune to said cultural influence), with evidence against one.
Hyothesis 3: Maya is unknowingly Jaffur's little sister, turned human to protect her from Vegeta, and as such she does not develop the aversion as it is entirely biological.
Assumptions: At least Five, with evidence against two.
Sorry, going to go with Hypothesis 1.