You share a common great grandparent. That would make you second cousins.
Second cousins once removed.
4
One of the Mothers was a grandmother and the other two mothers were her daughters, and each of the grandmothers daughters had two daughters. (1+2+4=7) +++ Not sure if this in the right category, but another variant of this riddle has a grandmother, mother and daughter going into a pub, one buying a round and apparently under-charged. The reason, of course, is that there are just 2, not 3, women! (The grand-child is not there.)
Your grand-daughter's brother is your grandson. Their mother would be your child. Her mother-in-law is not related to you, as you do not share a common ancestor.
grand father ;)
Grand-Nephew
Your grand daughter's husband is your grandson-in-law.
grand father ;)
They are your grand-nephews and grand-nieces or great-nephews and great-nieces.
They had a total of three children.
Michaela morales
He is your grandson by marriage or grandson in-law.
There puzzle seems to imply there are four people involved when, in fact, there are only three. Mother, daughter and grand daughter