It appears that many women get tattoos when they've experienced some kind of major life change or crisis. Those changes can range from the death of a loved one to marriage to childbirth or a new job. This isn't really a new practice but is one which is actually goes back thousands in traditional or tribal cultures.
A lot of women are starting to request larger customized tattoos on more visible parts of their bodies, like arms and legs. The ankle and lower back are common places for female tattoos, but the stigma towards women with tattoos seems to be disappearing so women are getting larger and more prominent tattoos such as chestpieces and full or half sleeve tattoos.