The following reflections might prove useful.
Ask her what her goal is. Presumably it is to heal an incongruity between her self perception/feelings/desires to be a man and her physical body which is that of a woman. Now she may frame it differently than this but i think it's important to see it in these terms. There is a perceived misalignment that is disturbing her.
She has 2 options. Option one is altering her body in hopes to conform it to her self-perception: to change her woman's body into that of a man. After taking testosterone for some years, her voice will drop and she will have facial hair as well as masculine musculature. She might think this is all she needs to align her body with her self-perception. But now she will agonize over her breasts and "need" to have them surgically removed. This won't solve it either, because now the focus will move to reproductive organs. If she chooses to have a pseudo-male anatomy constructed, assuming she survives the surgery, she will have severe health problems in exchange for a patchwork result that will not trick her mind into thinking it is a male anatomy. Having completed all the available procedures, her "dysphoria" will now center on other things: she will agonize over the fact that her hips are wider than her shoulders;her hands and feet are far too small to be a man's; her voice, while deeper, is tinny and feminine. She cannot impregnate. None of these things can ever be changed. In short, as the goal post moves, she will always be approaching a male body but can never possibly arrive at the finish line. She will now have spent many thousands of dollars;lost many friends and family members; had difficulties in employment, become permanently dependent on pharmaceuticals; incurred many serious health problems such as osteoporosis, cancer, surgical infection, and more... all of this and yet she will not only have failed to align her body with her self-perception, but she will also not have statistically reduced the likelihood of taking her own life. In other words she will feel just as dysphoric with the additional pain of having failed at something for which she sacrificed all that she loves.
The second option is to alter her self perception to conform with her female body. This path is more difficult as far as the act of the will is concerned and in the moment it is more painful to the emotions. However, it does not cost thousands of dollars; it does not destroy her health; it does not alienate her from friends, family and society; it does not leaver her dependent upon pharmaceuticals, and most importantly to her, IT IS ATTAINABLE. the mind/feelings/self perception is malleable and can be truly transformed. The body cannot. If she chooses this path, not only will she have a goal which can be reached and thus the hope of truly removing this "dysphoria" without destroying herself, but she will end up with a fully functioning anatomy of the sex which her mind (at that point) accepts. In the first scenario, even if she achieves the coveted results promoted by the doctors, all she has is a sterile, weak facsimile of a male body propped up by a constant stream of exogenous chemicals. In this second scenario she has actually been HEALED, and thus can perform all the functions of a member of her sex.
If she takes the time to seriously consider this it may help. Since you've already spoken with her at length, I recommend writing this out in a formal letter, from the heart. It may hit her differently. Pray and fast for her. Offer Masses. There is hope for everyone. Be assured of my prayers and that she is included in my intentions for my little Lenten observances. God bless you.