What does the cryptic crossword clue "Annie for one works on harp (6)" mean?

The definition is "Annie". The wordplay uses an anagram. anagram of ON + HARP = ORPHAN; definition: "Annie" The answer is ORPHAN.

Annie for one works on harp (6)

Daily Mail Cryptic #16851 | 26 Across | 2022-06-03 flower