The book I am looking for should have perhaps been called “The Happy Mountain” or the “The Jade Mountain” but nothing seems to match the google search of that.
I think it was a tween book from the 70s maybe earlier, but a young girl is staying with a much older aunt or grandmother. The older woman had, I think, lived for some time in her own youth in China, but was forced to leave with her family quite quickly. When leaving the country the older woman’s father gave her an ugly home-idol to carry with her to safety, an item she had always hated, but kept for years anyway as a memento of her father. Towards the end of the book, she discovers with the help of a out-of-favor nephew (I think) that inside the ugly idol was a jade village or jade mountain that she had loved as a young girl, obviously hidden in the hopes that she would find it sooner.