She has done covers for Black Mask, Dime Mystery, Detective Tales, and New Detective. Also Rangeland Romances, All-Story Love, New Love, Love Book, Love Short Stories, Love Novels, Romance, and Thrilling Love magazines.
In addition, she did interior illustrations for Argosy magazine.
Her website at http://gloriastollkarn.com/ has some of her cover artwork and contact information.
Surely a worthy candidate for guest of honor at a pulp convention.