She represented Gullbringa Golf & Country Club, in Kungälv, north of Gothenburg, Sweden, just as elder Swedish female stars Kärstin Ehrnlund and Helen Alfredsson.

In 1996 she almost gained her maiden LPGA victory, losing the Edina Realty Classic to Liselotte Neumann in a playoff.

Her caddie gave her the wrong club and she made a double bogey to drop into a six-way sudden death playoff, won by Se Ri Pak.

[16] At the start of 2002, Carin topped a Playboy internet poll as the sexiest women on the LPGA but declined to pose for them nude.

[18] In 2003, Koch gave birth to her second child, but still played well enough to be a captain's pick for the 2003 Solheim Cup, won by the Europeans in her native Sweden.

[25] The 2015 match, played at Golf Club St. Leon-Rot, Germany, ended in a U.S. win 14½–13½, after a strong American come-back the last day.

In 2021 Koch fulfilled the age requirement for the U.S. Senior Women's Open, and gained exemption by virtue of her position on the LPGA Tour all-time money list.

During her LPGA Tour career, they lived in Phoenix, Arizona, United States, with their two children, Oliver and Simzon.