Pesach 8:6
If you are an ‘onein’ [someone whose close relative died and the night
after the burial, rabbinically you should not eat any karbanos], you are digging
out a pile of rubble even though there might be a corpse there, one who was
promised that he would get out of jail, an old person who can still eat an
olives worth, you can slaughter the korban pesach.
On all these people, you do not bring the korban pesach just for them as the
korban might become posul. If any one of them became disqualified after the
slaughtering, they do not have to bring a pesach sheni.
Pesach 8:7
R’ Yehuda says you should not slaughter a korban pesach for only one
person. R’ Yosee allows it.
Even though many people are registered on the pesach, it is no good if none
of them can eat an olives worth.
You cannot make a group of only slaves, women, and young children.