Märta Ulfsdotter Swedish noble and lady-in-waiting (1319–1371) (1319–1371) Parents Bridget of Sweden Ulf Gudmarsson Children Ingegerd Knutsdotter Peter Sigvidsson Ribbing Arvid Ribbing Katarina Knutsdotter Siblings Birger Ulfsson Karl Ulfsson Cecilia Ulvsdotter Catherine of Vadstena Partners Knut Algotsson Sigvid Ribbing