Please explain how first, second, third and so on cousins work?

Question

Also what does ‘once and twice removed’ cousins work in that context?

In: 14

Answer 1

brother/sister – same parents

1st cousins – share grandparents

2nd cousins – share great grandparents

and so on.

Removed is by generation downwards. The children of your first cousins are your first cousins once removed. The grandchildren of your first cousins are your first cousins twice removed.