Not so much an AIBU as a query to other parents with adult DC about how you decided on a reasonable amount for them to contribute in "board".
DD (22) will soon be starting her first proper job. She has had various part-time and temporary things in the past but will soon be starting a real, full-time job with a decent salary. Although she hasn't restricted her search to the local area it just so happens that this job is quite close so she can live at home. That's great - we all get on well and it is lovely to have her here.
She has said (completely unprompted by us) that when she starts work she wants to start making a financial contribution for her keep. I think that is a good idea for all sorts of reasons, even though we don't exactly need the money, however I don't know how we decide on an amount.
I don't want to suggest something too small in case she feels patronised but, at the same time, we are her parents not her landlords so I don't want to be making money out of her. As a student she lived away in a different city so she is used to being independent and paying her way but I feel that living at home ought to be cheaper than being in your own place so she has the opportunity to save up for other things.
She does contribute to the household in other ways, i.e. she doesn't sit about expecting to be waited on but will muck in with housework, laundry, cooking etc.
So could I ask how some of you approached this issue with your own adult, working DC?