StormyWeather
You could make a netted crinoline underskirt for it. You can buy the material anywhere fabrics are sold. Measure the diameter of the crib and multiply it by 3; that's the length you would need. The width of the fabric (which is the height of the crib) is cut to size and hemmed. The edge that goes around the top, you sew a seam, preferably with crinoline boning. Once the seam is made, just sew a basic line stitch for the entire length, bunching it up as you go. You can fasten it with velcro. Or, you could go to a thrift shop and buy a crinoline skirt and simply alter it to fit your crib.