Do what he they said above, because this does not harm free will.
Keep away from violating free will through magic, spells, sigils, thought forms, violence and whatever. If you violate anothers free will, woe unto you, you foolish mundane, the universe will destroy you.
But the thecnique described above is good because it doesn't violate free will. She will always have a choice and will always act upon her free will. When she is weak and a victim and falls for your tricks it is her fault only. She could have used her free will to be strong and not react to you. No free will broken the universe will not punish you.
Never use black magick to force her. Never forget you cannot violate the free will of others…but of course you can put a little pressure on them, and bend them so that they use their free will just as you intend.