All great apart from things that have mothers???? Like every living thing in the world??

I don't get why vinegar has a mother. Too broad of a category I think. I would say novella before novelette. Haystack stands out bc its a saying whereas the other ones always have needles. I wish fold had more variety in the meaning, they all mean physically folding except the poker one.

The mother of vinegar is the expression for the slimy bacterial culture that breaks down alcohol into vinegars. Some bottles even come with the "mother" intact. Look it up if you're unfamiliar, it'll blow your mind.
Idioms and nonliteral senses of terms are perfectly common in Only Connect categories.