Children's book - World War II. Girl sent to live in another country during WWII as a toddler. New 'family' teaches her the piano and provides other cultural benefits. Eventually does not remember her original family

[Pam]

Girl sent to live in another country during WWII as a toddler. New 'family' teaches her the piano and provides other cultural benefits. Eventually does not remember her original family, but after return does adjust

[Katy]

I'm probably incorrect as the age is wrong, but could it possibly be Someone Named Eva?

[Rainbowheart]

Back Home?

[Nóinín]

Kirsti Comes Home: The Story of a Finnish Girl?

[Rainbowheart]

If it's neither of the two books above, might want to check out the War Guests in Children's Literature list.