小母さん
おばさん · obasan · JLPT N2 · noun
woman
小 small + 母 mother + さん = little mother, polite term for any adult woman
小 is a prefix that softens the word, 母 means mother, and さん is a polite suffix. Despite the root, it does not mean your own mother: it is used for any woman, usually middle-aged or older, and can sound casual or slightly rude.
小 — three small strokes around a central vertical
小 is a pictograph originally showing three tiny dots or specks, suggesting small particles or grains. Over time the dots became stylized strokes flanking a central line. The core meaning 'small' has stayed remarkably stable from oracle bone script to today.
母 — pictograph of kneeling woman with two breast dots
母 is a pictograph derived from 女 (woman) with two added dots representing breasts, marking a nursing mother. The earliest oracle bone forms show a kneeling figure with prominent dots on the chest. The meaning has stayed remarkably stable, denoting 'mother' and by extension 'female' or 'source/origin'.