I've been researching Carolina Helena Maria von Holst. (A word about her name: there are variations on spelling, depending on whether she was using the English spelling or the German or whatever. Plus, the surname von Holst was either written with a capital "v" or a lower case "v" - the family members themselves apparently couldn't decide. As it was, the "von" was adopted by the Holst family when they were in England and there is no evidence they were actually entitled to it!) Carolina was born in Danzig, Prussia, in the early 1800s - information from the Holst Birthplace Museum gives her date of birth as 1802, however her age in the 1851 English census suggests she was born about 1815. In 1834 she married a Dane, Joachim Heinrich Christian Friederichs, at St Pancras Parish Church. Her husband was noted as a widower and was a number of decades older than her.
Carolina was apparently a talented harpist. She was a pupil of Robert Nicolas-Charles Bochsa who was a rather colourful character (who incidentally died in Sydney, of all places) and she appears to have achieved some degree of fame in musical circles. I'm not sure that she was always known by her first name of Carolina - I've found one reference to her that suggests she used the first name of Friederike professionally. She also used many variations of her surnames: von Holst, Holst, Holst-Friedrichs, Friedrichs-Holst and Friedrichs (Friedrichs is the German form of Friederichs).
Carolina did at least one tour of Europe, in 1835-6, playing in Dresden, Berlin, Prague and Vienna, and possibly other places as well. She received very good reviews though the reviewers would have preferred her to steer away from the music of her teacher Bochsa as they felt it wasn't very good!
"Mad. Friedrichs’ play is in every respect excellent. Her passages are beautifully turned, and roll along like so many pearls, while her shake, considering it is on the harp, is admirable. We have heard nothing equal to her; and in addition to these advantages, she is a pretty, modest and amiable young person. May she let us hear something, occasionally, not by Bochsa!" (Supplement to the Musical Library, 1836.)
Family legend says that Carolina was employed as a harpist in the Prussian Imperial Court in Berlin, though it is unknown when. I have yet to find any definite evidence of this. Certainly by 1851 she was living in London in Paddington. Was it before or after this?
Did she have any children? Nothing has yet come to light. It is also unknown when or where Carolina died. The last we know of her for sure is from the 1851 English Census, when she was between about 30 and 50 years of age, depending on what date of birth you use. I do have information that says she toured Russia in 1837, France, Italy and the Netherlands in 1838, and then returned to London to teach, however I have no concrete evidence of this. But I'll keep looking!