Is this her?
California Birth Index
Name: Janet Elaine Matthews
Birth Date: 11 Jan 1936
Gender: Female
Mother's Maiden Name: Renfro
Birth County: Los Angeles
That is indeed her:
Jul 1949: Name listed as JANET ELAINE MATTHEWS; Dec 1952: Name listed as JANET ELA EGINTON; Jun 1955: Name listed as JANET E ADAMS; Jun 1961: Name listed as JANET ELA ADAMS; Dec 1963: Name listed as JANET E MORRISON; Apr 1971: Name listed as JANET ELA BRACKETT
Father: Thaddeus Matthews
Mother: Nora Renfro
Brother is Kenneth Lee Matthews, born 14 Mar 1939 in Los Angeles County.
Kenneth only just died last year! I wish I had seen this before then.
Name: Kenneth Lee Matthews
Gender: Male
Death Age: 76
Birth Date: 14 Mar 1939
Birth Place: Inglewood, Los Angeles, California, USA
Residence: Sandpoint, Idaho, USA
Death Date: 20 Mar 2015
Death Place: Kootenai, Bonner, Idaho, USA
Source location: Sandpoint, Idaho, USA
Spouse: Irene Brackett
Children: Cindy (Brian) Kramer of Sandpoint, Jeff; Cindy Ann
Parents: Thaddeus Matthews
Brothers and Sisters: Jan (Matthews) Brackett; Jan Brackett
I see that his wife and Janet's husband have the same last name. Related?
Here is Kenneth's obit. It seems they know she is dead, but perhaps her niece or nephew might claim her now?
http://www.lakeviewfuneral.com/memsol.cgi?user_id=1547792
I did send it to the link on Claimus, will post again if I hear anything back.