my mum uses words like " I dont care a fishes doodle" , when we are making excuses for something and "what a daffy" when she has a large portion of food. Can anyone tell me what's a fishes doodle and obviously a daffy is something large but where do these words come from.
Strangely enough, both 'doodle' and 'daffy' have been used in the past to suggest something idiotic, though I cannot quite see what that would have to do with your mother's sayings.
It occurs to me that you may have misheard 'doodle' when your mother was actually saying 'doodah'. That is just another variety of 'thingamy', a word coined to suggest something of little importance...and so ideal for use in dismissing a feeble excuse.
I would think that a fish's doodle (or doodah) is identical, anatomically speaking, to a man's doodle (or doodah). The usage here focuses on its size surely, ie. a fish's is extremely small. Analagous to not caring 'a gnat's chuff'?