I am never quite sure about the difference between 'second cousins' and 'cousins once removed' can anyone explain please? What relation is my daughter to my cousins grand daughter for instance?
Second cousins are the same generation as each other, once removed means they are separated by one generation, twice removed by two generations, and so on. So, your cousin's daughter is your 1st cousin, once removed; cousin's grand-daughter is your 1st cousin, twice removed. Your cousin's daughter is your daughter's second cousin; your cousin's grand-daughter is your daughter's second cousin, once removed.