I have never heard that she married between Joseph Cowles and Lambros Gusetis, but it is entirely possible. May I ask where you located this information?
Also, the 1900 Census that my friend gave me the information from includes an older brother of Olivia and John named Samuel: 1900 United States Federal Census about John Osburne Name: John Osburne Age: 9 Birth Date: abt 1891 Birthplace: Indian Territory, Oklahoma Home in 1900: Seneca Indian Reservation, Seneca Nation, Indian Territory Race: White Gender: Male Relation to Head of House: Son Father's Name: Eliot Osburne Mother's Name: Martha Osburne Household Members: Name Age Eliot Osburne 50 Martha Osburne 53 Samuel Osburne 23 Jesse Osburne 17 Van Osburne 15 Earnest Osburne 13 Oliva Osburne 11 John Osburne 9
This is the closest to finding Neva's family that I've gotten so far! Thank you for your reply.