A notary merely certifies that the signatures on a document are not forgeries by examining your identification at the time you sign the document. The notary does not certify the truth of whatever the document says.
If you want to prove that the two of you are sister and brother, you will need certified copies of your birth certificates show that you have parents in common, or -- if one of you was adopted -- a certificate of adoption. These should be available from your county registrar.
Your husband's sister is your sister in-law.
How could the relationship between Pip and Biddy be described?
nothing
They are Brother & Sister.
Being able to notarize a document has no relationship to whether or not someone is married. If you are properly authorized to notarize documents, and you follow proper procedure for confirming the signatures on the documents in question, then you can notarize the will, if not, you cannot.
Your husband's mother's sister is your husband's aunt. She is not realted to you.
A brother and a sister, both being children of the same parents, are siblings.
A man is his sister's son's Uncle. A woman is her sister's son's Aunt .
There is no relationship. You do not share a common ancestor. The connection is simply through marriage.
Brother and sister.
Your grandfather's sister's children are your 'first cousins once removed'.
There is no relationship. You do not share a common ancestor. The connection is simply through marriage.