Can anyone tell me the name of this book?

I remember this book I read when I was 8. It was a fairly long book but then again I was 8 most books where long. I remember a little girl, not sure what her name was I think it starts with an H. It's about her going to live with her grandfather up in the mountains, and the towns people don't particularity like him. There was also a boy named Peter but he did something with goats, I don't really remember. I also remember a woman at the beginning of the book, the girls aunt or something who brought her to the girls grandfather. The aunt or somethings name was DeeDee or something. Somewhere in the book the girl has to leave the grandfather. There may have been a person in a wheelchair. I don't remember.