The character for Aki means "Autumn", and Minoriko something like "Bountiful child" or "Seed-spreading child". Minori can also just mean "Harvest", and Ko "child", so her name could also just mean "harvest child"
It makes very much sense for Minoriko to be the younger sister who is the goddess of the harvest as the harvest comes after the changing of the leaves in the season.
In her official portrait, Minoriko's right foot is drawn like a left foot. It's supposed that ZUN likened her to a Japanese one-legged scarecrow which guards farms. The Japanese term for scarecrow, "kakashi", came from "kagashi", which means "smeller". This may explain why Minoriko talks about her smell in Reimu's scenario. Most artists, however, don’t draw her with two left feet.
Because she and her sister were ranked the lowest of the Windows characters in a year's annual Touhou Popularity Poll, there is a running joke in Japan that they are "original characters" with negligible presence in the games. There is a doujin anthology project dedicated to the Aki Sisters, perhaps to compensate for this.
In Double Spoiler, it is revealed that she runs a food stand that sells sweet potatoes.