So, I own a lovely copy of this book, and I'll probably continue to own it after this, though I cannot recommend it to anyone. 
This book was slow and ridiculous in premise. It feels like something they hand you in a utopian society to convince you you're at peace or whatever. It's all very calming imagery and random statements on God. The men are all-wise and kindly while most of the women are either middle-aged and villainous or old and saintly. I'm not sure what Johanna Spyri was trying to get at, but it's weird how obviously done this dynamic was. 
Also, Heidi, for her part is eternally happy and characterized by her innocence and goodness. She's meant to drive the story with her goodwill but she's an unrealistic child. I don't know if the author has ever met any children but all the 4 to 6 year olds I know are nothing like this.