Strictly speaking, there aren't any balconies in The Westing Game. I think the question refers to a hallway. In chapter 9, Sydelle hits upon the bright idea of using the elevator as a kind of bulletin board where you can post all kinds of messages for everyone to see. In Sydelle's case, she posts a note asking for the return of her lost papers. (Though unfortunately, she doesn't get them back).
In any case, one of the notes in the elevator states that six clues have been found in the third floor hallway—written on Westing Toilet Tissue, no less. But these so-called clues are really just a bunch of jumbled-up words designed to insult Turtle Wexler:
BRAIDED KICKING TORTOISE ’SI A BRAT
This strange message seems to be referring to Turtle's fashion for wearing her hair in braids as well as her unfortunate habit of kicking people in the shins. That's why the cryptic message refers to her as a brat. And as for the tortoise, well she's not a tortoise but a turtle. The word "tortoise" has just been used to make the message sound mysterious, when its real meaning is actually pretty simple and can easily be worked out by anyone with half a brain.