What is the ruling on slaughtering a single 'aqeeqah for seven family members using a cow that has not been designated for its owners?

The 'aqiqah is not valid if it is sacrificed for more than the number prescribed by religious law, such as sacrificing one sheep for two individuals, or a cow for more than seven. A cow is sufficient for seven, by analogy with the hady (sacrifice during Hajj) and udhiyah (sacrifice of Eid al-Adha). If a cow is sacrificed for seven children, but the one for whom the 'aqiqah is being performed is not specified, then it is not considered an 'aqiqah, because "every child is ransomed by their 'aqiqah." However, if the one for whom the 'aqiqah is being performed is specified but not named at the time of slaughter, it is a valid 'aqiqah, because naming the newborn at the time of slaughter is recommendable but not obligatory. The Sunnah for the 'aqiqah is two sheep for a boy and one sheep for a girl. The basic requirement of the Sunnah is fulfilled by sacrificing one sheep for a boy, and one-seventh of a cow takes the place of a sheep.