Inspired by Matthew_R's post and the enthusiastic response to share similar posts, I'll start this thread here for anyone interested in the idea of posting samples of handwriting from friends and relatives of the past (or present, if you like). Any ideas welcome. Even your own writing.
Here is a picture of my grandmother (fathers mother) at age 18, in 1912, and the earliest sample of her writing I could find at the moment, written in 1922.
Here she is in 1971, and a sample of a letter she sent my parents a few months earlier. Still very legible at age 77. The Mike she is referring to is me.