Im assuming the female staffs that created Linlin's kimono look are part of Black Maria's household/residence. Well, Black Maria herself is dressing in Kimono and wearing a headpiece just like the Linlin's sillhouette we've seen. It's definitely interesting to sew how this plays out. Black Maria could be a native to Onigashima/Wano, thats why she chose to dress traditionally rather than wearing typical BP's clothes.