cool-then start the countdown to that magic day in october when (as i regularly told my kids) 'it's no longer child abuse in the eyes of the law-it's simple assault'
i kid, but i went round and round with my dd because of her lack of housekeeping while living at home. i've never bought into the 'it's MY room if i don't mind it YOU shouldn't' argument-i OWN the room (and the adjoining rooms everyone uses), i choose the level of cleanliness that has to be maintained. it was one thing when she was finishing her senior year-another when she started college. she had the option of living at home and doing the short commute to school-with the expectation of certain things, cleanliness included. she didn't like it so after freshman year she moved out....out with roommates, lots of roommates-the place they lived in was GROSS but she continually blamed it on the roommates so then she wanted her own place but found out pretty quickly that no one rents to a single college student w/o a cosigner, and this cosigner wouldn't sign unless the place was kept up.
is her place spotless? nooooooooooooo, but she no longer has roommates to blame OR roommates (or mom) to come in behind her and run dishes, shift the wet load to the dryer, take out the garbage.... her landlord knows college students and gives random 24 hour notifications of unit inspections. after psycho cleaning sprees that caused her to miss out on social plans and left her exhausted and aching she's gotten better. it's still a work in progress. i wish with dd there had been something to drive her to be less messy-her younger db is'nt psych obsesvily neat but his concern for the high cost gaming systems and computers drive him to keep his space much cleaner lest he let dust and debri cause damage.
i guess what i'm saying is-you are dealing with ADULTS here, not little kids. while your dh's mom obviously did'nt teach him adult responsibilites on this front you can still teach them to your dd. maybe talking to your dh about despite your dd almost being an adult he still needs to model appropriate behaviors might help (i've seen parents do stuff they don't want/like to do because they know it's best for their kids).
again-good luck.