#there's always room for it being either a mistake on GRRM's part or an intentional in-universe misunderstanding/invention

[myimaginationplain]

Could someone explain to me why exactly Alysanne Bulwer is referred to as the head of house Bulwer if she has a brother, especially one old enough for Megga Tyrell to be engaged to? It might've made sense if he were a baby brother (although not entirely, because even baby boys are ahead girls in the line of succession), but it doesn't at all if he's older or of a similar age.