Update: He made a separate account for his daughter and scheduled her appointment the same day/time as his.
However, the Embassy website in France seems to be having difficulty today and when he went to print the confirmation, the site crashed and he lost the page to print the confirmation.
He did manage to print the confirmation for his daughter though.
He currently has a ticket in for that and to ask if all is well for his and his daughters simultaneous interviews.
If anyone has any info or tipe, it's greatly appreciated!