Final answer:
The available resources do not specifically state how Atal, Malala Yousafzai's brother, found out about her shooting. It is likely he learned from his family or the media as the shooting was highly publicized. Malala became an internationally recognized figure after surviving the attack, leading to widespread media coverage.
Step-by-step explanation:
The question about how Malala's brother, Atal, found out about the shooting does not have a directly quoted answer in the provided resources.
However, in the context of I Am Malala: The Girl Who Stood Up for Education and Was Shot by the Taliban, we can understand that Atal might have learned of his sister's shooting through his family or media reports, as is common in such traumatic situations.
Families often learn about tragic events involving relatives from both personal communication and news sources. It's also possible that since Malala Yousafzai became a public figure after the attack, the news spread quickly locally and internationally, making the information accessible to her family members.