I see that your examples are getting at how character components work in Chinese, but it's oversimplistic. 女（nǚ) means "woman", but 娘 (niáng) means "mother". It's composed of the functional components 女, which is just a hint at the meaning for disambiguation purposes, and 良 (liáng), which is a hint at the pronunciation. Similar for 妮 (nī) with sound component 尼 (ní) and a similar historical meaning and development to the English word "lass". In the second and third cases the 女 is a semantic functional component, but it's still a different character with a different (if similar) meaning.
re: What I said about Kanji; I don't speak the language so perhaps I misunderstand how things work. My impression was that the mapping from character to meaning was looser in Japanese than it is in Chinese.
Written Japanese is much more ideographic than written Chinese. Japanese spelling is determined, such as it is, by semantics. Chinese spelling is determined by sound. Thus, 女的, 娘们, and 妮子, all meaning 'girl' or 'woman', have no spelling in common because they are different words, while Japanese uses 女 for "jo" and "onna" despite a total lack of any relationship between those words.