So what do you need to know ? In the 1911 census she is living with 'Albert' Castein but her Rossiter children are living in various places as servants or relatives.
I do have a copy of Frank and Ketura's marriage but I would assume that Ketura then married Castein in the Registry Office which are not online.
Frank Rossiter died 1905 and is buried Abney Park cemetery.
I'm afraid I don't like the Genes site and have always used Ancestry or Findmypast.