@Rawlda0I would also object to a guest arriving with lots of laundry to do. It has happened to me too. You are right to ask for an additional fee for this or politely direct her to the local laundrette if there is one. You are not running a free laundrette and she would not get this for free at a hotel either.
If you have not done so already, I suggest you include something in your house rules about both laundry and security/alarms so that future guests hopefully understand this before arriving. They might not bother reading the rules, but you have this as back up should you need to contact Airbnb about it.
Do you have a security deposit on your listing? It might be worth mentioning to the guest (in the nicest way possible of course) that it would also be in her interests to use the alarm, because your insurance wouldn't cover a theft otherwise and it would have to come out of her deposit.