Every one or two years between 1937 and 1942 Oppel exhibited paintings in Bremen, participating in each of five collective exhibitions organised by the , the nationwide association of female artists and art promoters of which she had become a member soon after its creation in 1926. Neither her move to Bavaria nor – at least till after 1942 - the war appear to have inhibited this. She built her reputation with buyers and critics, through her characteristic landscapes depicting the , the fenland surrounding Worpswede in the otherwise mostly unpeopled countryside north of Bremen. From her time living and working on the island on the Chiemsee there are paintings of boats and the Chiemgau landscape, along with portraits of the potter, his wife, and the family with which she and her son lived there. These paintings are still (2020) in private collections.