The St Louis Public Library obituary search website shows a burial permit in the 13 June 1969 publication of the St Louis Post Dispatch for Bettie Phillips. Here is a link to the obituary search webpage, there is also a link on the page to search by year:http://www.slpl.org/slpl/gateways/article240117800.asp
It appears there was no obituary published. A search of the Catholic Archdiocese burial website does not have a listing for Bettie Phillips, nor does findagrave.com.
You could request a copy of the death certificate from the local health department office or the Missouri Bureau of Vital Records. Here is a webpage describing the process for requesting a death certificate:http://health.mo.gov/data/vitalrecords/applications.php
David in Pennsylvania