What does the cryptic crossword clue "Lady-in-waiting, her motto 'Be prepared'? (6,2,2)" mean?

The wordplay uses an anagram. anagram of HER + MOTTO + 'BE = MOTHERTOBE The answer is MOTHERTOBE.

Lady-in-waiting, her motto 'Be prepared'? (6,2,2)

Daily Mail Cryptic #16814 | 13 Across | 2022-04-13 flower