US D617090 S1
The ornamental design for a child's backpack, as shown and described.
FIG. 1 is a front perspective view showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top plan view; and,
FIG. 7 is a bottom plan view.
The broken lines shown in FIGS. 1-7 form no part of the claimed design. For the sake of clarity, the lower strap contains a break, which represents the strap as having no particular length.