It took me a minute to figure out who Margaret was. I have been so far back in Dutch names for the last little bit seeing a name in English kinda threw me...lol. But now that I know I am really excited about your reply. Is John related to the family or did he just happen to have the same last name? Here is what I have so far about Fredricha. Can you verify this or tell me if what I have is wrong.
Fredrika (spelling changes a lot) van der Woude - daughter of -
Roelf van der Woude and Betje Pluger
Roelf van der Woude - son of -
Jan Weits van der Woude and Wipke Berends vander Veen
Betje Pluger - daughter of -
Frederik Wilhelm Pluger and Grietje Jacobs de Boer
Betje was also sister to - Anne Pluger and Kathrina Pluger
Frederik Wilhelm Pluger - son of -
Hermanus Heinrich Pluger and Katrien Lewiesen Kloek
Grietje Jacobs de Boer - daughter of -
Jakob Karsten de Boer and Anna Haaijes de Boer
Also I would welcome the opportunity to talk (email) to you about all of this in detail and see what else you have include current information. I have no information on Henry or his ancestors and have had trouble finding any. Feel free to email me directly - firstname.lastname@example.org
Hope to hear from you soon!