Family in the End

I don't think there is any relationship besides the fact that she became "sister" of Katiba in a ritual when she gave him a wristband and he gave her his necklace; they met by chance when she sent the dog after the kids that where bullying him; and that's all The Warrior has after having lost his son. I believe it is more like a spiritual coincidence, he had a vision of the Himalayas when he spared the girl's life and it was like a spiritual conversion that made him start in his journey.