Make over-skirt. Using 20 in. fondant roller with orange guide rings, roll out medium blue fondant to 16 in. circle. Place over pale blue fondant.
Using craft knife, carefully cut out front panel, exposing pale blue pleats. Be careful not to cut into pale blue fondant. Remove excess fondant.
Insert doll into cake. Using hands, carefully smooth medium blue fondant over cake. Fill middle hole with excess fondant, if needed, to keep doll straight. Continue smoothing fondant up to waistline.