Oh, I'm sure she'll figure it out.
But since you're being so thoughtful about it, why don't you write her a note around the middle of August:
"I'M BUSY FOR THE NEXT SIX MONTHS, SO EITHER SHUT THE **** UP, OR ELSE GET LOST, ***** !!! AND TAKE THE BRAT WITH YOU, WILL YA? CUZ I KNOW YOU CAN'T KEEP YOUR TRAP SHUT!
Cap'n T. "