The ornamental design for children's furniture, as shown and described.
FIG. 1 is an isometric view of my new design for children's furniture from a front perspective;
FIG. 2 is an isometric view thereof from a front perspective with some unclaimed features broken away to better show the claimed design;
FIG. 3 is another isometric view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a front elevational view thereof;
FIG. 7 is a rear elevational view thereof;
FIG. 8 is a top plan view thereof; and,
FIG. 9 is a bottom plan view thereof.
Stippling in the drawings provides shading to represent three-dimensional contours of the design and is not intended to indicate surface decoration. The broken lines in the figures represent portions of the children's furniture that form no part of the claimed design.