This is what I have learn today.
John has two brothers and a sister.
Question : How many sibling John has?
Answer: John has three siblings. ( Three siblings not included John)
In Mandarin : 我们四兄弟姐妹。( Included herself/himself.)
In Malay : Saya ada empat orang adik-beradik. ( means she/ he also one of them- included)