This is a Message Board Post that is gatewayed to this mailing list. Classification: Query Message Board URL: http://boards.ancestry.com/mbexec/msg/an/UW.2ADI/1986.1 Message Board Post: Kris wrote, "My Mary O'Brien bn. May 1875 was probably boarding with someone in San Mateo County in 1910. She would have had a son, John, 12 years old and possibly other children. Can't find her because she wasn't Head of Household and I don't know who she lived with. I just know she didn't live with her husband, a merchant in SF." Kris, although she may not have been head of household, if Mary were boarding with a family or listed as lodger, etc., she *should* be indexed -- that is, UNLESS the head of household also had the surname O'Brien or unless the enumerator missed indicating Mary's surname. In 1910, there is a boarder Mary O'Brien born circa 1879 in California, but there is no John born circa 1898 living in the same household. Do you know Mary's maiden name?