Rent/housekeeping from older working teenage children

[Oddsocksrus]

Hi
Question from my neighbour, her 19 year old dd is working full time, not in the greatest paid job, but earning.
She has volunteered to pay her parents some rent/housekeeping money each week but they don't know what is the going rate?
I'm not much help, I paid my parents £25/ week 20 years ago so don't have a clue what would be right now.
Any suggestions?

I would set it at 30% of her net income. And then save it up for her and give it to her when she finally leaves home.

I like your thinking
Knowing my lovely neighbour she thinks the same way too, their lovely dd volunteered to make a contribution which I think says a lot about their good parenting