I believe I do have a timeline of events that you might find revelatory.
She also gets a small plastic cowboy from the cracker, which she gives to her grandson, Benji. Benji is warned not to snatch by his mother, Hilla, who reminds him that “Level 3” behaviour is expected.
Deborah chooses to pull her cracker with her grandfather, Walter. Vanessa indicates to Walter that his cracker is on his side plate. Deborah wins, but questions if she has to rip up her hat. She asks if that tradition comes from them being a bit Jewish.
Hilla tells her that lighting the candles is because they are a bit Jewish, but that the hat ripping comes from the Wilkinson side. It transpires that the tradition dates back at least as far as Uncle Newt’s childhood.