Sexual minority women face a plethora of structural, socioeconomic, and interpersonal disadvantages and stressors. Research has established negative associations between women's sexual minority identities and both their own health and their infants' birth outcomes. Yet a separate body of scholarship has documented similarities in the development and well-being of children living with same-sex couples relative to those living with similarly situated different-sex couples. This study sought to reconcile these literatures by examining the association between maternal sexual identity and child health at ages 5-18 using a US sample from the full population of children of sexual minority women, including those who identify as mostly heterosexual, bisexual, or lesbian, regardless of partner sex or gender. Analyses using data from the National Longitudinal Study of Adolescent to Adult Health (N = 8978) followed women longitudinally and examined several measures of their children's health, including general health and specific developmental and physical health conditions. Analyses found that children of mostly heterosexual and bisexual women experienced health disadvantages relative to children of heterosexual women, whereas the few children of lesbian women in our sample evidenced a mixture of advantages and disadvantages. These findings underscore that to understand sexual orientation disparities and the intergenerational transmission of health, it is important to incorporate broad measurement of sexual orientation that can capture variation in family forms and in sexual minority identities.