Why didn't Miles give his family some of the water to drink?

Miles didn't give his family some of the water to drink because he was likely trying to conserve it for survival, prioritizing his own needs in a dire situation. He may have felt that sharing the limited resource could jeopardize their chances of enduring until help arrived. Additionally, there might have been a sense of hopelessness, leading him to believe that it wouldn't make a significant difference for his family's survival.