Kate Harris was employed the London studio of William Hutton & Sons to produce artistic silver from 1899 to c 1905.  Her work is often hallmarked for Goldsmiths and Silversmiths who were retailers as well as manufacturers.  See Dr Stephen Pudney’s articles on Kate Harris in the Decorative Arts Society Journal Vol 22 “A marriage of art and commerce: Kate Harris and the arts and crafts silverware of William Hutton & Sons” and 2015 Volume 39 “The mystery woman of English art nouveau”.