Are all your hens new layers? My guess would be yes since most of the eggs in that carton look small. Perhaps her egg looks extra large because your other ladies haven't got into their "big girl" egg size yet. Usually, they start off small and gradually get larger. I'm not saying all your ladies...
Is her egg green? In the first pic it looks brown🤷 Anyway, I have an OE that lays XL army green eggs, when she first started laying they were tiny, then one day she laid an XL egg, and that has been the norm for the last 2 1/2 yrs. She's a pretty lady!