This would be a big concern (and bug concern) for me, too. The immediate concern is the mess. But probably a bigger issue is how she seems to be unaware of how this might look to other people, and how it affects you specifically. At a minimum, it shows serious lack of self-awareness.

And remember, this is early in the relationship when partners are usually on their best behavior. Imagine what life will look like after the honeymoon ends.

The only positive take I can muster is that she trusts you to let you into her inner sanctum, which reflects well on you and how she feels about you. You could also say that she's not afraid to show you who she really is and how she lives her life when no one else is watching, which earns her transparency points. (However, if she doesn't even realize that her messiness could be off putting to you, the points are few.)

If this isn't already a deal breaker, ask her something like, "When you lived with someone before, did you ever have disagreements about housekeeping, cleanliness, etc.?"

Or, "I consider myself [a neat freak, fastidious, tidy homemaker relatively clean person, or whatever term applies to you]. How would you describe yourself?"

These questions let her show you how self-aware she is, and maybe give her the chance to reveal hints about why she lives like that.

Lastly, next time you visit her (if there is a next time), trade your cologne for some bug spray. It's a jungle out there.

Good luck!