What should I say in a personal loan to a friend to make it legal?

I have bought a computer for a close friend to use for school work and work stuff. I told her that she can use it but that if something happens that we decide to separate and not be friends any longer for whatever reasons, that it is still mine and will go with me. I told her that I was going to write something up and have her sign it stating this but want to make sure that her soon to be ex husband can't claim it in the divorce. I have looked online for a free printable doent and can't find one. what would you suggest that it say or me do. I just want to cover myself and don't want her soon to be ex to possible try n take this also. Any help is appreciated.