It is useful to examine the balance of power between you and your mentee and to be clear about what you are trying to achieve. Are you empowering your mentee to work out what is best for them by using all the skills and sensitivity at your disposal or are you trying to impose your own agenda? Decide which of these is your purpose and then work on your skills in order to best achieve your goal.
One model to help you look at the continuum of power is the push/pull model which can be found here.
Also see Issues of Power in the Establishing the Relationship section.