Aru Shah and the Tree of Wishes (Aru Shah #3) by Roshani Chokshi

War between the devas and the demons is imminent, and the Otherworld is on high alert. Fourteen-year-old Aru Shah and her friends are sent on a mission to rescue two “targets,” one of whom is about to utter a prophecy that could mean the difference between victory and defeat. Turns out the targets, a pair of twins, are the newest Pandava sisters, though the prophecy says that one sister is not true. When the Pandavas fail to prevent the prophecy from reaching the Sleeper’s ears, the heavenly attendants ask them to step aside. Aru believes that the only way to put the shine back on their brand is to find the Kalpavriksha, the wish-granting tree that came out of the Ocean of Milk when it was churned. If she can reach it before the Sleeper, perhaps she can turn everything around with one wish. Careful what you wish for, Aru . . .