There are no guarantees, but to increase your chances of this being a female you can:

1. Keep temp in low 70's
2. High nitrogen and low potassium for the next 2-3 weeks.
3. No plant stress! No pruning or bending which damages the stem.
4. High humidity.
5. Fewer hours of light (e.g. 14 hours).
6. Heavy blue spectrum light., low red.

Good luck!