On the topic of earning allowance for household chores, do you think there is a certain amount of responsibility that young adults should share simply because they are just part of the household? And if so, how do you differentiate between 'this is your contribution as a member of our home' and 'this is extra that you earn money for'?
Here is one way you could work out giving chores to your young adult or teen: Make a list of chores that need to be done in your home. Divide it into two lists: chores you will pay for and chores you won’t. Sit down and talk to your teen or young adult about which chores they would prefer doing over the others. Let them pick one from each list.
So it works like this, when they pick one from the list that they get paid for, they have to pick one from the list where they don't get paid money. For example, if your daughter wanted to do the kitchen floor once a week for money, she would then need to pick a chore off of the other list, like dusting the living room, and do it as a responsibility to her family. Then follow through by letting your teen or young adult know that they will get paid when both chores are completed.
On a side note, don't add too many chores to your teen's to-do at a time, one chore from each list is a good start. Wait until it is a solid habit, usually two months, before adding any more.