group of mothers
That's a good question.
What do you call group terms such as swarm and ream?
A group of scholars
A group of ants is called a colony or an army.
A group of warlocks is called a coven as in witches
Your Uncle.
grand father ;)
they are your cousin
If it is a group of calves born from different mothers than you call them a herd of calves or a group of calves. If it is two calves born at the same time from the same mother than they are twins, just the same as human offspring would be called.
Your great grandfather
grandma/pa
cousin
Your mothers.
Mothers of Invention
I call my mother mom
Mothers is more than one mother. Mother's is something that belongs to a mother. "The mothers group is meeting Tuesday." "My mother's car is in the shop."
A fetus.