Thought you might like to hear the outcome:
Finished her clean.
"That's perfect, thanks. Now I've seen your work's good, can you do numbers 22,24 and 26 as well, please? Here's the cash for the lot". They are all old dears and she looks after them.
I did them all the next day. Whil I was doing number 26, the guy from 22 came out and said "I like your work, so can you pop along and do number 18 as well, please?"
So the moral is: Never assume the worst.
Vin