In the end I think the best gauge is you. If you feel comfortable with your current BF% and weight then that should be more than enough.
JuhQman, I absolutely agree with you. However, there are so many women who starve themselves to go extremely low BMI and go extremely low BF%.
Ideally, to get 6 pac abs, you need to aim to less then 20% for women. But for those with very low BMI, when they go less than 20%, they get only boney belly not 6 pac abs.
Or low BMI and low BF% but still ugly love handles.
You wouldn't believe it but there is a slim madness in Japan. These people do not realize that they are slowly killing themselves with starvation diet. And I thought BMI is a suitable meter as far as health is concerned.
Maybe higher BMI is okay. But when you are lower BMI, it is a problem.