Thanks! I would increase their wcs for starters- atleast 50% 1-2x a week as two goldies in a 20g is a bit much. Add some veggies into their diet, too. My guess is this girl is likely an oranda/oranda cross and is just starting wen development although I will admit, its a bit odd to see this all at once. Wen goldfish will develop white 'pimples' that are indicative of growth on their heads. You may some fuzz or strings come out of the 'pimples' which is perfectly normal. Theory has it that wen goldies actually have a very low grade infection during wen growth periods but its nothing to be concerned about. A nutritious diet, lots of veggies and pristine water are the best things for them (nitrates below 10ppm). If you notice anything else unusual or something with her changes, please let us know!