Possible Relationship ?

[Gadget]

I can't really say much apart from if you have  one relationship + another relationship

e.g.

 140 cM + 150 cM = 290 cM

So Ancestry and other sites will say you have 290 cMs in common. This puts it into the 2nd cousin range. Instead, it's really (say) 3rd cousin from one line and 3rd cousin from another line.

[Mart 'n' Al]

What would be the paper double relationships in your example?

Martin

[sugarfizzle]

Martin, Two explanations -

https://genetics.thetech.org/ask-a-geneticist/double-cousins-share-one-quarter-their-dna

https://www.famlii.com/what-is-a-double-cousin-genetically/

Basically, although you are cousins you share twice as much DNA as would be expected.

This also works for double second, third cousins etc.

Regards Margaret

[sugarfizzle]

Just think of the effect of identical twin cousins marrying identical twins.

The children of each couple would probably share near identical DNA!

Lafrowda. Sorry if this thread has gone a bit off course! Most of the replies are from regulars here.

Please let us know how you get on.

Regards Margaret

[Lafrowda]

Thank you for all the thought that has gone into my question.  It seems that at the age of 76 I have discovered I am not who I thought I was.  The relationship is half niece. Her grandfather being my father (hitherto unknown). Her grandparents and my "parents" occupied the same farm prior to my birth.  Thirty years of barking up a wrong tree.