For females, in general, avoid going below 15 % bodyfat. 

Women have many variations of hormonal problems associated with anything lower than 15%, such as their menstruational cycle being disturbed, more menstruational bleedings, loss of hair, and more.

Genetic differences mean some woman may have less problems than others.

If you do not plan on doing bodybuilding shows or attempt to be a professional athlete, avoid a drastically low bodyfat percentage, especially if your primary goal is just to see your ABS.

Consult your gynaecologist, and doctor, should you consider such dramatic fat loss.

Related Questions:

1. What fat percentage do I need to be to see my abs?