Children's book about a disturbed adopted sister from Vietnam

Question

It was written sometime in the 80s. It was a large but slim hardcover book. It was about a girl whose parents adopted a girl from an orphanage in Vietnam a few years after the war ended.

The adoptee had lost her entire family and seen horrible things so she was mute. Would not show any feelings or talk to any of the family. The original daughter in the family was a talented ballerina and tried extra hard to help her new sister.

Nothing worked and at the end of the book the ballerina was so frustrated that she started banging her head against the wall The adopted sister started laughing and the ballerina sister ended the book feeling happy and relieved that even a small breakthrough had been made and felt there was hope for the future for the adopted girl to become a real sister.

The book was part of a series called Life choices, Lives in crisis, or something like that. My school had the entire series but this is the only one I remember reading. I cannot find any information on the series itself now either.

Answer 1

Miracle of Time: Adopting a Sister by Jane Claypool Miner seems to match. Description and cover from Amazon:

A young girl tries everything she can think of to reach the withdrawn five-year-old Vietnamese orphan her family has adopted.

It's part of Crestwood House's Crisis series: A series of hi - low books dealing with individual, typical crisis situations.

The book is available online at the Internet Archive. The scene of the ballerina (Shirley) banging her head on the wall happens on page 60:

Shirley turned and put her arm up on the wall, then she hit her head against the wall. She pretended to hit her head very hard, though it really didn’t hurt. She wasn’t acting for Kim anymore, she was just acting out some of the way she felt...

Her back was still turned and she was still hitting her head against the wall when she heard the small laugh. It sounded like a small, clear bell.