There are several reasons to believe that Fred and Lola had no such child:

• Lola already had a daughter Flossie from her first marriage (Flossie Minshaw) and that daughter was still alive in 1930.
• Flossie's age in the census if 7 and she is listed in age order as is typical. However, Fred and Lola had a stillborn son May 01, 1922, who would have been 7 years at the time of the 1930 census, so there is probable conflict in the age given. Furthermore, Lola had no history of children less than two years apart, and was 44 years old in 1922. It seems unlikely she would have had two children that close together at that age, unless they were twins.
• The birth index available on Ancestry shows three births for Fred and Lola, ending with a 1922 birth. The birth has no name and no gender recorded. The index includes births dated in the early 1930s, so no likely birth record for Flossie unless she was a twin and one line was placed in the index for both births.
• We have the death record for the stillborn son from Ancestry.

We need to view the birth record referenced in the on-line birth index to see if a twin birth is indicated. If not a twin, then we should suspect the daughter relationship. Perhaps they took in a neice or grandaughter and listed it as their duaghter. Or perhaps they adopted a child and reported her incorrectly. If she was a twin, the we need to look out for a death or marriage in the 1930s, or for a reference in an obituary.