The death certificates and obituaries of at least one of Nancy's Flamm children would hopefully have the father's name and possibly her maiden name.
I believe her son Nicholas Flamm died Feb 15, 1934 in Somerset County.
If her children were to inherit anything through their father while they were minors they may have had guardians appointed. The record would most likely be at the Somerset County Orphans Court Office and most certainly list who their father's was. Sometimes when a father owned land the heirs sold the land immediately after his death, the mother's death or even much later. In Pennsylvania deeds are recorded at the Recorder of Deeds in each county.