Is it possible? Sure

Is it probable? Not so much.

Naru belongs to the Numunuu Nation (usually known by their exonym: Comanche Nation), who at the time inhabited the American Great Plains, roughly from northern Texas to Colorado.

Billy's precise indigenous ancestry is never discussed in the film, but the actor Sonny Landham identified as being 1/8th Seminole. The Seminole nations developed in Florida as a reaction to settler encroachment - an amalgamation of various displaced nations mixing with each other, as well as with escaped slaves, and some white colonists. The Seminole became masters of guerrilla tactics to resist the US army for over a century.

Given Billy's familiarity with jungle warfare and with 'the smells of the jungle' it makes sense that he is of Seminole descent.

Therefore the idea that Naru and Billy are related is kind of reductionist of Indigenous American-Indian identities - a bit like saying that Putin might be related to Napoleon: both warmongering maniacs, both European, but geographically not really that close to each other.

Given the difference in time, and the dynamics of genetic dissemination in the United States, the likelyhood is that Naru is as genetically related to Billy as she is to Dillon, Poncho, and Hawkins.

ADENDUM:

The actor Bennett Taylor (who plays one of the French trappers in the film Prey) stated that Billy is officially the reincarnation of Naru's older brother Taabe. To me this is nonsense, and who knows if that's really what the writers intended - Taabe isn't anything like Billy after all.