Bringing Asha Home by Uma Krishnaswami, illustrated by Jamel Akib

From the back of the book:
It's Rakhi, the Hindu holiday special to brothers and sisters, and Arun wishes he had a sister with whom to celebrate. Soon it looks as if his wish will come true. His parents are going to adopt a baby girl named Asha. She is coming all the way from India, where Arun's dad was born. The family prepares for Asha's arrival, not knowing it will be almost a year until they receive governmental approval to bring Asha home. Arun is impatient and struggles to accept the long delay, but as time passes he finds his own special ways to build a bond with his sister, who is still halfway around the world.