As a matter of ethics and law, adults enjoy wide berth in securing hormonal and surgical interventions to align their bodies with their desired gender appearance. In contrast, the exercise of choice by minors is more constrained, because they can be less well situated to grasp the nature and consequences of interventions having life-long effects. Even so, some minors hope for body modifications prior to adulthood. Starting very young, some minors may assert atypical gender identity: those with female-typical bodies assert a male identity and those with male-typical bodies assert a female identity. This assertion of identity is atypical only in a descriptive sense, because it is uncharacteristic, not because it is normatively unacceptable. Not all minors persist in their atypical gender identities, but some do. For those who do, it is desirable to minimize unwanted secondary sex characteristics and to maximize desired secondary sex characteristics. I outline here a theory of respect for decisions by minors in regard to hormonal and surgical interventions that help align their bodies with their gender identity. Of particular ethical interest here are body modifications for fertility preservation since certain interventions in the body can leave people unable to have genetically related children. In general, I will show that the degree of respect owed to minors in regard to body modifications for gender identity expression should be scaled according to their decision-making capacities, in the context of robust practices of informed consent.