If food or drinks other than water aren't allowed in the bedrooms at all, you also don't have to worry about dishes or half-eaten food or food-related trash.

I'm also a firm believer in setting up my (probably ADHD) kid for success as much as possible, which means I have rules like 'no food in the bedroom' because that way I don't have to get mad when she inevitably forgets to bus her dishes promptly or knocks her chocolate milk over on the rug.

OP has two choices: don't look, or offer more support than you think an eleven-year-old could possibly need to clean her room. My ten-year-old gets entirely overwhelmed when faced with the disaster that's her room, but I can come in and tell her to pick up all of the [category] and she can. Sometimes she'll ask for me to set a timer for five minutes so that she can clean as much as she can get done in that time; basically whatever works for your kid.

I follow this gal on Insta, nottheworstcleaner, a social worker who volunteers to clean the spaces of people living in hoarder conditions due to mental health issues, and her suggestion is to start in a one-square-foot area and then gradually move around the space a square foot at a time. This method also has the benefit of having immediately visible results, which picking up all of the [object] might not, because while picking up all of the stuffed animals will have a big impact, picking up all of the markers probably won't. (That's also why I start with something big and impactful, like stuffed animals, and gradually work down to smaller things as the floor gets cleaner.)