This longitudinal study investigates an English-French-Turkish-speaking seven-years-old female child’s repertoire combining two Indo-European languages, English and French, and Turkish, which is an Altaic language. Language attrition has mostly focused on first language (L1) attrition, and to a lesser extent on second language (L2) attrition. Third language (L3) attrition, however, has been mostly overlooked, and more attention has gone to adult language attrition after migration or after institutional language learning. Most research has in addition focused on only a subset of target languages (TL). This paper therefore addresses the attrition of child L3 (Turkish) attrition ‘after remigration’. The findings show selective regression with structurally assigned morphology and confirm the findings of previous studies showing that the younger the informant, the more attrition is likely to occur.