Those kinds of things have a way of sitting and sitting and sitting and sitting, until suddenly they get used up. The origami activity books I bought for the girls sat and sat there until they did 10 projects. Then they sat and they sat until yesterday we did a few more and my 7.5yo folded a couple on her own (I helped interpret the instructions). This is one example in a thousand I could list exactly like this.
It sounds like your daughter is a bit more disorganized than you are and is content with that. If that's true, some of that is age appropriate and some of that is nature. DD1 still needs to learn some tidying-up habits (age appropriate), but her operating habits are generally organized (nature). My youngest, 6yo, moves from one game to the next (age appropriate) and her games are sprawling and chaotic--the more, the merrier (nature). Both love when I help organize their space, and that indeed seems to spark new energy and creativity, but they also do just fine creating their own sense of organization. Their organizational needs (regarding our space, our time and our projects) are a bit different from mine, and while I think sharing good habits with them can be helpful, often they find new ways to fulfill their needs that I haven't thought about.
(Warning: my daughter is watching and she is asking I write in different color "ink")
My youngest will indeed do project on top of project. Mostly, the joy is in the doing and not as much in the keeping (until it is, and it turns out the piece I recycled last week and is long gone is the one she is asking for). DD1 doesn't seem to care that much either way. The keeping is more my thing. DD1 recently has liked to keep lists of horses she wants to collect for her Farm and we are working on ways to keep these lists together that works for me (so I am not asked to find them) and for her (something she enjoys and can work with). I bought a binder for her (which is sitting and sitting and sitting there, BTW.....) but she has instead started adding them to a silver-sparkle colored composition book I bought for her years ago (which had been sitting and sitting and sitting there!)
Unschooling at our house can seem a bit random at times. A few things are a given everyday, for the most part, but other things seem to move in fits and starts. If the ideas are mine--like beading, knitting, woodworking, origami, writing in pretty composition books, etc.-- those things tend to sit (and sit and sit and sit) for quite a long time before they dive into it for a day, then not again for a month or more.
I guess these external ideas take time to intrinsically incorporate on a regular basis (I hope that makes sense). I also struggle with the notion that my girls are just not excited about the same things I loved at their age. That's even harder to let go of than the interests I have picked up as an adult. I also am learning to let go of focussing on how the girls organize their projects. They do them in a different order, with different techniques, and I struggle with that simmering frustration, but at the same time I know that learning those things for themselves is just as important as the project they are working on. So, the end result looks a bit more chaotic to my adult eyes--not as polished, sometimes not even recognizable in any context except their own (if they say it's a barn, then it's a barn, and the fact that the toy cow fits inside clinches it!)
Long story (with perhaps more information than was necessary) short, I would let that journal sit in her backpack for a long time. Don't put it out where she will see it. Let her forget about it for a while. She is telling you in her 5yo way that now is not the time. Since this is the unschooling forum, this is the time to say, gently, "mama, let this one go for a while". You can share the important things in other ways for the time being.