The fact that she has gone & bought this book without talking to me about it indicative perhaps of some of our issues
You're having issues and you're trying to get her to open up about them. She's obviously put some thought into this and found out that couples journal is a thing, it made sense to her, and she ordered one in hopes that it might work to help you move forward.
She bought a book without talking to you, she didn't put the house on the market without talking to you.
It's been very difficult to get her to do any talking at all.
Maybe she finds talking difficult, maybe she feels that the prompts in the journal will help her open up.
She says she still wants the relationship but it feels like the willingness to work on issues isn't there at this time.
I think that she is showing willingness, she's not bought a copy of Razzle. She thinks the journal might help and she's asking you to try it.
Has let me wondering therefore what next if anything.
What's next is you try the journal with an open mind. Otherwise it's stalemate.