Apocalypse bunker

The three kids are all kind to each other like siblings and fight like siblings too. The Apocalypse has begun and your best friend, (any name, boy) and you (any name, girl) managed to find a secret underground bunker, and on the way you found a 2-year-old toddler (any name, boy).......you and your best friend are 11 years old........3 days in and you two treat the toddler like your own