I wonder how much of this is shaped by skills and old job perceptions?
A lot of women leave their education and / or career early to have kids and raise them. Thus, when they return to the work force as the youngest enters the school system, they often end up in lesser skilled and lower paid jobs. Because this means they don't have much of a career path and it's a secondary income, they tend to just stay in a job they find acceptable to them - thus a longer time in a lower paid job is common for this demographic. Those facts would go a long way to explain some of the tenure and salary level items shown.