Ever wonder why Ami is knitting constantly before she becomes Dark Mercury?
Though its clear that the knitting here is a symbol of their friendship, it can read a little deeper.
The French word “ami/amie” (アミ), meaning friend, is pronounced identically to the name Ami (亜美) in Japanese, furthermore the stem verb “編み”, also read as “ami” means “to knit”. So in a sense, Ami is connecting together their friendship through the process of knitting, all of which is “ami”. Ami is really the force bringing them all together. Ami ami-ing her ami.
As their friendship weakens early in the series, when everyone becomes preoccupied with their own issues, Ami knits harder and harder trying to bring everyone together, but eventually when she slashes the mittens she makes, she is effectively, breaking their bond of friendship. Literally breaking the “ami” from them in three different senses.