Will giving them hormones and surgery stop bullying?
The answer has been published in multiple studies, here's just a few:
de Vries AL, McGuire JK, Steensma TD, Wagenaar EC, Doreleijers TA Cohen-Kettenis PT. Young adult psychological outcome after puberty suppression and gender reassignment. Pediatrics. 2014 Oct;134(4):696-704.
"After their GRS [gender reassignment surgery ], many participants (89%) reported having been never or seldom called names or harassed. "
Cardoso da Silva D, Schwarz K, Fontanari AM, Costa AB, Massuda R, Henriques AA, Salvador J, Silveira E, Elias Rosito T, Lobato MI. WHOQOL-100 Before and After Sex Reassignment Surgery in Brazilian Male-to-Female Transsexual Individuals. J Sex Med. 2016 Jun;13(6):988-93.
"When considering the facets, sexual activity, freedom,
physical safety and security, financial resources, and health and social care were improved after SRS [sex reassignment surgery]..."
Nobili A Glazebrook C, Arcelus J. Quality of life of treatment-seeking transgender adults: A systematic review and meta-analysis. Rev Endocr Metab Disord. 2018 Sep;19(3):199-220.
And finally a metaanalysis found that quality of life is significantly diminished in comparison to the general public before any medical/surgical treatments were performed, but afterwards, their quality of life was no different to the general population.