Children ghost book

I am trying to remember the name of this book I read when I was in either elementary or middle school, I am now 19 in college. It’s fiction and I believe it was about a girl who recently moved into a neighborhood. The most important part of this story was that in one of her neighbors attics or upstairs windows, she could see a girl her age. I’m pretty sure she was a ghost and that the main character of the story needed to set her free? It was a pretty thrilling book from what I remember, at least for children that young, which I am guessing is the targeted audience of this book. This book was pretty small, about half an inch wide and the cover should show the main character in front of the house with this ghost girl. It would be nice to reread a book that used to be so important to me when I was younger.

Maybe Stonewords by Pam Conrad and/or the sequel, Zoe Rising?

A much longer shot, but also possible: the Haunting with Louisa books by Emily Cates: the first one is The Ghost in the Attic.

>2 beyondthefourthwall: None of these seem to be what I’m looking for but hopefully they could eventually lead me to the book I’m thinking about! Thank you so much!

Revisiting, wondering if this could be one of the supernatural mysteries by Cynthia DeFelice, such as The Ghost of Fossil Glen.