She was one of the possible candidates to be the sister who got married in a space suit.
Dawn had been engaged. As part of her engagement announcement, she tried to train chickens to spell her name, but failed somehow. (Daphne thought it could have been done easily using corn and electrical wire.) (Pawn Of Shadows)
Scooby-Doo! Mystery Incorporated
Daphne headed off to school, saying goodbye to her sisters standing in a row. (Beware the Beast from Below)