FIG. 1 is a right front perspective view of a fluid-filled decorative element for a child's shoe, showing my new design;

FIG. 2 is a front elevational view thereof; the rear (not shown) is plain and unornamented;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a perspective view thereof on a reduced scale, the broken line showing of a shoe being ornamental only and forming no part of the claimed design.