Good for her. Imprisonment includes a restriction on voting, movement, and other amenities free citizens possess, but that does not mean exclusion from medical care. The number of people in this thread saying she should pay for it (while incarcerated mind you) is laughably high. If she had developed cancer or tumor, almost no one would object to treatment, as that would be cruel and unusual to deprive her. But GRS is somehow not acceptable?
Prison should be about rehabilitation, not punishment. Being there is the punishment. And for those of you complaining that taxpayers are paying for this, there are literally millions of dollars spent in your state on things that don't directly affect you. And I agree that all trans people deserve a chance at treatment, not just inmates. That's an issue with the US healthcare system, not prisons paying for the well being of their residents.