Full siblings vs half siblings

[Louis]

Hi there,
I am entering data for some babblers I am looking at to create pedigrees of their breeding. I have entered chicks from the same breeding attempt with same parents but sometimes they come up as only half brothers and sisters instead of full brothers/sisters in the 'relatives' tab. Could this be because your programme is designed to have a maximum of 2 chicks per breeding attempt and the babblers can have 4?

Thanks in advance
Louis