Searching for great aunt's birth and death information

Trying to find my great aunt's birth and death, cause of death, born 4-28-1915, died 1930, unable to find grave or listing in census, daughter of Cyrus Alfonso and Sitty Staley, last of 9 children.

How do I proceed?  I have been searching for a great aunt named Valeasse Staley, born 4/28/1915 believed in Lawrence County, Oolitic, Indiana, died in 1930, unknown place.  Not listed in census of 1920 or 1930.  Parents Cyrus Alfonso and Sitty Staley,  Cannot find birth certificate or death certificate or cause of death.  Drs. Dollens and Benham were physician  at that time.  Last of 9 children, everyone else has grave or marker except her.  Unknown if she had deformity or defect from birth, not listed anywhere in institution but possibly not kept at home.  Any suggestions or help would be appreciated.  Have searched for almost a year.  Help please!  Oolitic or Bedford, Indiana