His family socialized within the upper echelon in the capital city region, and he stood behind the establishment of Høvik Church and the use of Fleskum farm by a group of painters.

Through his mother's lineage he was a first cousin of Erika (Nissen), Ida and Thomasine Lie, and a nephew of Erik Røring Møinichen.

[1][2] Frithjof Plahte lived in England as a timber merchant for several years,[3] and some of his children were born there.

From 1882 to 1898 Maggie was married to painter Christian Skredsvig; later to Michael Strøm Lie (a son of Frithjof's cousin Thomasine).

[1] The year after Frithjof Plahte died, his household was registered in the census as having several servants; Otto Haug who administered the farm, three housemaids, a cook, a coachman, three male farm helpers, a milkmaid, a welder and a childkeeper, in addition to some family members of these employees.