I checked newspapers.com and found two articles related to Norma Henne in "The St. Louis Post Dispatch".
While the articles so my list the parents names, one lists the maiden name and siblings and the other confirms the maiden name.
First, on February 7, 1963, page 1, there is a death notice for William Vahle. Siblings are: Walter Vahle, Florence Taylor and Norma Henne. Here is the clipping:
https://www.newspapers.com/clip/5575572/st_louis_postdispatch/
Second, on June 22, 1968, page 9, there is a death notice for Louis Henne. His wife is listed as Norma Henne (née Vahle). His mother is listed as Myrtle Vahle. Here is the clipping:
https://www.newspapers.com/clip/5575588/st_louis_postdispatch/
Hope this gives you some good clues to help find Norma's parents