Frist of all, let me say that I honor your intention to help out this friend. We all know how difficult these kinds of things can be. I have a few thoughts on this and just wanted to share them. I am an old (but still very hot) witch, and have been doing this for quite a few moons. I have learned (and learned and learned) many things the hard way.
My "advice" (if you will) is to be very careful. "Spelling" for another person is often times what we are guided to do. However, it has been my experience that these times should be on very rare and special occasions (which this may very well be- only you will know!). The problem is that we must learn to pick and choose how we expend our energies on behalf of others. It not, we will be burning multiple candles, every hour, of every day... forever.
Most of the time, if I am guided to help someone, I try to empower THEM to do the actual "spell". This may mean anything from providing a dressed candle and a written invocation to suggesting a book on meditation.
(You can alway do a little somethin-somethin, privately, on the side, if you feel you need to)
But, when we give the power to them, we, well,... actually give the power to them.
And that truly is the greatest gift we can give to another.
Remember this:
To the untrained person,
If you do a spell and it works, it's your victory. If you do a spell and it doesn't work, it's your fault!
I know, little one, you will do what is right for you. Blessings in your endeavor. )0(