das Geschwisterchen
Translation
little sibling, baby brother, baby sister
Examples
Meine Schwester bekommt bald ein Geschwisterchen.
My sister is getting a little sibling soon.
Das kleine Geschwisterchen schläft viel.
The little sibling sleeps a lot.
Grammar Patterns
to get ((sth.)) My sister is getting a little sibling soon.
Similar Words
Brüderchen (little brother), Schwesterchen (little sister)
Etymology
From 'Geschwister' (siblings) with the diminutive suffix '-chen'.
Memory Tips
The suffix '-chen' in German makes things small and cute, so it's a 'little sibling'.