The ornamental design for a non-slip toddler seating pad device, as shown and described.
FIG. 1 is a top plan view of a non-slip toddler seating pad device showing my new design and being a mirror image of a bottom plan view;
FIG. 2 is a side elevated view of the non-slip toddler seating pad device; and,
FIG. 3 is a top perspective view of the non-slip toddler seating pad device, wherein the areas in phantom are for clarification only and form no portion of the claimed invention.