Yes. I understand that posed group shots can be an important requirement to parents and others within your family and I am happy to take them. However, organising and taking these shots does not happen quickly and I therefore usually shoot between 6-10 groups in total. Realistically, this will take at least 25-30 minutes to complete.
It is also important to take into consideration that during the group shots it isn't possible to continue documentary coverage of you and your guests.