I have a trans-niece. I do hope they do hormone blockers soon. The male hormone onset of large bone structure etc cannot be reversed. If she were to decide in a year, that she really wants to be male, stop the blockers and the body proceeds with testosterone driven biology. I worked with a trans woman last year. Her challenge at work was exactly that large male bone structure that made her "stand out".
Blockers are desirable initially for pre-hormone teens rather than going straight to estrogen/testosterone treatment and seldom will a provider prescribe the hormones immediately as this decision can be temporary.
A 2008 study found 61% desisted from their transgender identity before reaching the age of 29,[17] and a 2013 study found 63% desisted before age 20.[18] A 2019 clinical assessment found that 9.4% of patients with adolescent-emerging gender dysphoria ceased wishing to pursue medical interventions and/or no longer felt that their gender identity was incongruent with their biological sex within an eighteen-month period.[19]
It is a challenging time for the immediate family. I'm grateful my niece is alive. Prior to this decision he had been a severe cutter having hidden it for 18 months until a friend turned him to the Nurse at school. My nephew took him to counseling where she remains a regular client and for that I continue to be grateful.