What is the share of a son's daughter (bint ibn) when accompanying a half-free daughter?

Primary text

If a son's daughter is present with the half-free daughter, she receives one-third (al-thuluth). This is because if the daughter were entirely a slave, the son's daughter would receive one-half, but if the daughter were entirely free, the son's daughter would receive one-sixth. Her partial freedom causes her to be restricted from the full one-third, and her half-freedom restricts the son's daughter from the one-sixth share.