[2] In 1901, using her inheritance, Nicholson moved to California, and soon opened a small shop in Pasadena, selling Native American handicrafts such as baskets and weaving.
She traveled extensively in the rural western and Southwestern United States, worked with local dealers to build her collection, and corresponded with East Coast collectors to sell the objects.
[9] As a member of the "Anthropological Society," she joined a tour group that visited horticulturist Luther Burbank in 1905, in Santa Rosa, California.
Notable artists whose work was presented under her supervision include Honolulu-based Frank Montague Moore,[15] Southwestern painter Joseph Henry Sharp,[16] Danish silversmith Georg Jensen,[17] William Victor Higgins,[18] watercolorist Pop Hart,[19] Emil Fuchs,[20] Dutch cartoonist Gustave Verbeek,[21] Grace Hudson,[22] Agnes Lawrence Pelton,[23] undersea painter Zarh Pritchard, and Irish-born illustrator Power O'Malley.
[12][26] Nicholson was an active charter member of the Zonta Club of Pasadena, and hosted meetings at her home, including a 1929 Christmas party attended by Amelia Earhart.
[7] Another large collection of items purchased from Nicholson was bequeathed to the Montclair Art Museum in New Jersey, by Florence Rand Osgood Lang.