"Lydia [sic] Southard's Famous Apple Pie (unknown songwriter, ca. 1921) This song is about Lyda Southard, the infamous "Lady Blackbeard" of Idaho who poisoned at least four husbands with her apple pies laced with arsenic. Her sensational murder trial in Twin Falls, Idaho was in 1921. The song likely dates to that year. Lyrics appeared in WOII with the note "Folksong sung to the tune of "Annie Laurie"." First lines of verse:
Oh, Twin Falls farms are bonnie in the middle of July,
And 'twas there that Lyda Southard baked her famous apple pie."


Good bio here (on p.3).

And another here just under 1/2 way down.