What's the Name of That Book??? discussion

I read this book that was a Middle school level book from late 90s/early 00s that may have "wolf/wolves" in the title or a theme about them. I remember certain plot details but not the title or author. I remember a boy (name unknown) lives with his dad in a cabin in the woods and befriends a neighbor kid who may be female (name unknown), his parents divorced after his one year old sister died in car accident after she somehow got out of her car seat and thrown through the windshield (i believe). I think she liked the character big bird. One night his dad wakes him up and says that him and his mom are divorcing, and he was given the choice between his mom and dad and he chose his dad. His mom may have been crazy or depressed. I remember towards at some point he talks with the neighbor and their parents and ends up breaking down in front of them and tells them everything like missing his sister or something.

Lone Wolf by Kristine L. Franklin seems to match your description.

Google Books preview: https://books.google.com/books?id=Ewr...
There are different cover images.

Google search of Goodreads:
site:goodreads.com "middle grade" wolf dad "cabin" woods parents divorced sister died car accident

I copied a few book details to the topic header. Feel free to edit it.

Kris wrote: "Lone Wolf by Kristine L. Franklin seems to match your description.

Google Books preview: https://books.google.com/books?id=Ewr...
There are..."

That is it! Thank you so much! I have been trying to find this book for over 20 years!

Great news! Glad you found your book, Miles.