“My 1st Cousin 3 Times Removed”
How old are you? /s
You wouldn’t believe me if I told you! ;>)
that would be the 1st cousin of the authors great grandparent...
or something...
1st Cousin 3 times removed means that the child was the 1st cousin of a great-great-great grandparent. Your cousin’s children are your 1st cousins once removed. etc.