Vintage Royal Doulton Bunnykins dishes are not safe for children to use. This dish tested positive for 80,000 ppm Lead & 1,916 ppm Arsenic. 90 ppm Lead (& up) is unsafe by modern standards.
Target Threshold Earthenware Easter Bunny mug: 217 ppm Lead in the black accents, 90 ppm on the white glaze.