The Spanish pronoun 'ella' meaning 'she' or 'her' comes directly from the Latin demonstrative pronoun 'illa' meaning 'that' (feminine). This evolution shows how a word used to point to a feminine object or person ('that woman/thing') became specialized as the third-person feminine pronoun in Spanish.

A related Spanish word is the definite article 'la' ('the' for feminine nouns), which also developed from Latin 'illa' but underwent more phonetic reduction. You can also see this root in Spanish demonstratives like 'aquella' ('that one' - feminine), which preserves more of the original demonstrative meaning from Latin.

While English 'she' is not related to Spanish 'ella', we can find the Latin 'illa' root in some English words borrowed through French, such as 'elle' (a feminine pronoun sometimes used in English fashion contexts) and in some technical terms where 'il-' or 'illa-' appears as a prefix meaning 'that'.