Karen Johansdatter Schjelderup's mother was Karen Jensdatter Collin (born 1689, died 1763). Her father was Jens Hansen Collin (born 8 Nov. 1651 in Kolding, Denmark, died 8 March 1708 in Trondheim). He was bergassessor (associate judge at the Trondheim court of mines), which had jurisdiction over all the mining establishments in the northern part of Norway.
The Collin family definitely came from Denmark, but was firmly established in Trondheim in the late 1600's, and continued to play an important role in the city until the early 1800's.
An article by Olaus Schmidt "Bergamts-assessor Jens Hansen slekten Collins norske stamfar" was published in Norsk Slektshistorisk Tidsskift vol XVI p 222-235. According to the article, Jens Hansen (he did not use Collin as family name) apparently moved to Norway in the mid 1660's as clerk or deputy in the service of magistratspresident Lorentz Frantzøn. His date of birth is quoted from a memorial poem by Marcus Volquartz to be November 8 1651, and his birth place is given as Kolding, Denmark. An older article by Jens Colding in Personalhistorisk Tidsskrift, Tredie Række, 4.b states that his father was a former rittmester (captain) who had served under King Fredrik III, his mother was Anna Cathrine and that he had a sister by the name Marta Sofia.
Jens Hansen died in Trondheim 8 March 1708. His wife, Karen Olsdtr Tønder, had 12 children in their marriage.