Today, many children worldwide grow up in bilingual or multilingual families. This study explores early literacy development in Russian-Hebrew bilingual families in Israel. It studies the contribution of the home literacy environment (HLE), the language of communication, and the nature of the maternal writing support in Hebrew and Russian, to children's early literacy skills in the two languages. Participants were 61 Israeli children (4-6 years old) and their mothers. The mothers completed questionnaires about home literacy activities in both languages and were videotaped while supporting their child in writing a list of eight words in Hebrew and Russian. Children's early literacy skills (phonological awareness, letter knowledge, and word recognition) were assessed in both languages. Results showed that mothers adjusted their writing support not only to the child's skills but also to the particular orthography. The HLE and aspects of mothers' writing support predicted their children's early literacy skills, not only within each language but also in cross-language models. The literacy activities provided at home and the nature of mothers' support seem to link to the children's literacy outcomes. The results stress the importance of parents' explicit efforts to support children's early literacy skills in both heritage and societal languages.