Thank you to everyone who has helped with this. I now have a lot more information about my Dutch ancestors. One thing I still cannot find, is what happened to the estate of my great great great great grandfather Thomas Jackson, after heo died in Amsterdan in 1834 leaving his young family as orphans (his wife Hannah died in 1833, a year before him).
He seems to have been quite wealthy but we cannot trace what happened to his estate after he died. Nor can we find out who cared for his children, Thomas Leonard, John Hilton, Alexander Matthew and Mary (Marij) Jane, until they became adults. We have no idea where they lived, who they lived with, how they were educated, whether they inherited any money, before they became adults.
If anyone has any suggestions about how to find out more about their early lives in Holland and what happened to their father's money, it would be appreciated.