Teaching Dharma Has Great Benefit
A student was going to prison to serve out an earlier sentence. A nun who knew her was very concerned that she was unable to protect the woman from having to go to prison. The nun felt hopeless, limited in her ability to benefit sentient beings, since she couldn’t do anything to prevent this from happening. Rinpoche gave the following response to the nun.
This kind of temporary help doesn’t really eliminate the root of suffering, samsara. But your teaching Dharma to sentient beings has great benefit. That eliminates the very cause of samsara. Teaching Dharma gets rid of the very root of problems, including the problems of prison and drugs.
You can realize the deep benefit you are giving to sentient beings by teaching Dharma, and not feel totally helpless, because you were unable to do anything about this specific problem.
Your friend can do retreat in prison. She can make her life meaningful in prison. You told me that when she was first arrested and put in prison, she did prostrations to the 35 Buddhas and that probably when she had to go back to prison, she would do that again. Then she would not mind being in prison.