This inquiry examines the vocabulary development of bilingual children when neither of their languages has a minority language status. With both languages having high relative prestige, it is possible to handle the influence of exposure variables: age of onset, length of exposure, and frequency of exposure (FoE) to both languages. Parents of 40 English-Hebrew bilingual children, from mid–high socio-economic status, completed the vocabulary checklist of the MacArthur-Bates Communicative Development Inventory (CDI), and a background questionnaire. Two-thirds of the children displayed balanced bilingualism, reflecting the relatively higher prestige of the two languages. FoE appeared as the main exposure variable, other than chronological age that contributes to the preservation of L1 and acquisition of L2 by bilinguals who are dominant in one of their languages. Analysis of individual data displays how using a bilingual CDI can help distinguish children who are at risk for Specific Language Impairment, testing both languages and producing provisional bilingual norms, or employing conceptual vocabulary with monolingual norms.