He is married to Loltje Halbes Scheper.
They got married on September 1, 1910 at Schoterland, Friesland, Nederland, he was 25 years old.Source 3
https://allefriezen.nl/zoeken/deeds/0fe9aa60-e524-38ce-a3d4-ebf3eb2a315e?person=88447d1f-b677-0b64-15b3-02e96f40c160
https://www.delpher.nl/nl/kranten/view?facets%5Btype%5D%5B%5D=familiebericht&cql%5B%5D=%28date+_gte_+%2206-03-1965%22%29&cql%5B%5D=%28date+_lte_+%2220-03-1977%22%29&query=%28harm+scheper+hielkema%29&coll=ddd&redirect=true&identifier=ddd:010690621:mpeg21:a0129&resultsidentifier=ddd:010690621:mpeg21:a0129&rowid=1
https://allefriezen.nl/zoeken/deeds/8f6fa587-4eb2-6398-0832-6c0cbd30e2b7?person=823e1395-03be-3d5a-8fbc-8b65308a8d00