Below you can find the August 23 1959: she joins charlie brown's family as his younger sister Jeopardy Words Answer. The answer to August 23 1959: she joins charlie brown's family as his younger sister has 5 letters. This clue belongs to the A peanuts timeline category and is part of Jeopardy Word Level 1691. If you scroll near the bottom you will find other clues and answers part of level 1691