The ornamental design for an objectholding harness for children, as shown and described.
FIG. 1 is a front perspective view of an object holding harness for children, showing my new design;
FIG. 2 is a rear perspective thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top view thereof;
FIG. 8 is a bottom view thereof; and,
FIG. 9 is a rear perspective view of the object holding harness for children shown with an attachable tether. The tether is shown separately in FIG. 9 for ease of illustration.