A cross-referenced search for Mariel-Ci gave me 2009 pieces. Marni - Ci listed 2012 - current.
Not that it's a big deal. Marni is clearly just more active than Mariel.
Well yeah, Marni does mostly wardrobe styling whereas Mariel and her partner Rob are great at editorial styling. Mariel also styled Ciara for those Grammy parties she attended earlier this year too.