Some of my best students were women, and some of my worst were men.
On the other some of my best were men, and some of worst were women.
As far as I can see, gender is irrelevent.
It's unfortunate that people end up with abysmal instructors. A bad instructor can make a brilliant student seem poor, whilst a good instructor can help a not-so-brilliant student achieve to the best of their ability.
As for "you will need x amount of hours...", I always told any enquirer that the miminum hours required are xxx but most people take yyy to get their licence.
I always told people I can't predict how long any particular individual will take as some people start well but run into difficulty later, others have difficulty early in their training but breeze through later stages. However, there are some general guidelines: younger is better than older, a life history of operating vehicles is better than one steering water buffalo, etc etc
Also that fewer the hours that people tend to have when they would achieve any particular stage of training then the greater the variability of hours realised eg. compare the minimum/median/maximum hours taken to achieve a PPL (40 min), compared to a CPL (150 min). A long winded way of saying that early stages vary more than later stages when a larger experience base has been acquired & skills have consolidated, I suppose.