ENThe aim of the paper is to analyse the different linguistic behaviour of two siblings, both Lithuanian Heritage Language Speakers. The respondents were born in Australia to a family of Lithuanian war refugees and acquired Lithuanian as their L1. The findings reported in this paper are based on in-depth semi-structured interviews, a film retelling task and verbal fluency tests. Quantitative and qualitative analyses are performed in order to determine the peculiarities of the sibling's linguistic behaviour, their patterns of language use, and strongest factors influencing heritage language maintenance. [From the publication]