She looked up at her flock of cranes hanging from the ceiling. Her brother Masahiro had hung them up for Sadako.
Literal
Ceiling [from-から] hanging own [possessive-の] cranes [possessive-の] flock [to-に] eyes [object-を] directed. This [topic-は] older-brother [possessive-の] Masahiro [subject-が] Sadako [for-のために] hung-up [did for her-てくれた] thing was.
This references the true story of Sadako Sasaki, who developed leukemia from the Hiroshima atomic bombing and folded paper cranes (千羽鶴) hoping for recovery. ぶら下がっている is a relative clause modifying 鶴の群 ('flock of cranes'). 目をやった ('directed her eyes / glanced at') is a literary expression for looking. ~てくれた indicates Masahiro hung the cranes as a kind act for Sadako's benefit — the giving/receiving verb くれる marks the speaker's (or subject's) gratitude for the action.