“I’ll put my fascinator on” is a reference to the show/movie “Oklahoma!”
Aunt Eller says it to Curly, after he suggests that he’ll take her to the box social (in that famous surrey with the fringe on top) instead of her niece Laurey.
Unfortunately I mis-quoted. The precise exchange is as follows:
AUNT ELLER. Bet you come over to ask Laurey.
CURLY. Whut ‘f I did?
AUNT ELLER. You askin me too? I’ll wear my fascinator.
A “fascinator” is a triangular shawl or scarf, usually crocheted, that can double as a bonnet. It was a popular item with frontier women.
Also unfortunately, the grand prize (i.e. for being the first in with the correct answer) got mixed up with the Halloween candy and eaten.
Sorry about that.