You do NOT want to mess with this Victorian lady. Judging from this 1906 photo by Percy C. Bryon, she could probably take you down.
According to an issue of American Heritage from 1972, the photograph is demonstrating New York-based Dr. Latson's method of female self-defense:
A Dr. Latson of New York taught both jujitsu and a mode of protection -- apparently suited to rainy days -- that employed the umbrella. The photographs at left of “Dr. Latson’s Method of Self-Defense,” taken by the noted photographer of city life, Percy C. Bryon, in 1906, illustrate these modes for warding off a street bully, fair weather or foul.
H/T Reddit user tapenade21.