My intuition is that she lives or once lived in a house within 60 minutes of Montessori Private Academy of Rockford. When I attempted to find her home under that assumption it lead me to a house that closely resembles the pictures that we have of her room.
For all those who are helping with the search you may want to check out Tree Swallow Bend in Loves Park, IL which is within 60 minutes of Montessori. Many of the houses there don't have publicly available pictures. So it may not be easy to conclude she's in one. Perhaps the reason why its so hard to find her is because she was living in an old family home and interior pictures aren't available online.
Disclaimer:
If anyone thinks I am giving out too much info here (since we don't want Tiny to figure out her address, only pixie) let me know and I'll edit this post to make it more vague.
DM it to me, if you want, and I'll take a look.
I haven't actually looked that far up yet.
It just seems bizarre to me that I would manage to narrow it down to Rockford, because of a stupid logo next to her, which I believe fits the Montessori one, and months later, in a fit of rage due to my constant mocking him, Destiny confirms that it is indeed Rockford.
And to be clear, I'm not even going by his statement alone, that picture that he shared, of Rock Valley College, is 100% Rose's. So this definitely isn't the case that he saw me believe that it's Rockford, and maliciously found a random picture of it to feed into my delusions, to waste my time. That picture is 100% real.
Sure, Rockford is next to Chicago, so it's not as insane of a coincidence if I narrowed it down there, due to wrongful assumptions (Montessori), but still, just look at all the other possibilities.

Which makes me believe that I was probably right, it is the Montessori logo.
That makes two things, Rock Valley College, and Montessori Private Academy, which are both found in Rockford, and have relation to her in some way or another.
In my experience, this kind of coincidences, do not happen, or at least, I haven't experienced them before.
Now, it's my personal assumption that it's far more common for a college that you go to (even tho we don't even believe she actually went there) to be further away from your home. Meanwhile, something like a middleschool, if a sibling goes there, or a parent teaches there, I actually expect it to be right next to the home, or close by. Keep in mind, from the sounds of it, her parents are protective of her, so even tho one of the first things that I did was check for college apartments/dorms, I also have never thought that she lives alone.
Also, Destiny in different occasions, in the logs, asks her what she did and she responds with "family stuff" or "hanging out with family", and also he asks to call her, obviously his typical calls that he did with Lav/Lauren/Lelayna/and any other girl that he's sexting with, and she responds that she can't right now, or today (can't remember which), again, which implies that she lived with her parents and wasn't in sort dorms.
Also, there's the fact of her room being a corner room, as I've posted, from what I've learned of the layouts in Rockford, this is most common in 3-4 room homes. I definitely have found a few apartment layouts that have it, with only 2 bedrooms, but with everything we know, and my new assumptions, specially since she lives with parents, I wouldn't be surprised if it's a 3-4 bedroom home.
One bedroom for her parents, one for her, and either an extra one for a sibling, or two extra ones for multiple siblings.
And, specially, after familiarizing myself with the state's, but specially the city's decour, this Montessori area seems to be one that constantly checks almost everything that we are looking for in order to find Rose. But really, it could genuinely be anywhere in the city, we don't really have much in terms of information.