Hi Gordon, I have also traced my line back this far, and I have been working with a Rockland County Genealogist who has been providing much of the info regarding the original Dutcher families who settled in New York Rockland County area. Here is what she sent me:
DUTCHER (yeDUITSCHER) family in America
1)Wilhelm Janszen “Van Heerden” was born in Heerden, Holland. m. 12/18/1656, Leentje Martens, widow of Jochem Piterszen Kuyter. Three children: Roelof, Willimpie & Jan Willemszen
2)Jan Willemszen ye Duitsher – first appears 09/01/1689 in Ulster County, NY.Purchased land 08/05/1669 in Esopus, NY.He and his wife, Margaret (Grietje) Corneliss were in Kingston 1663.he served in the Military from 1673 to 1687. Nine children.
3) Barent Dutcher. b. 1678, Esopus, NY. M. 1) 1701, Maretje Conckling. 4 children: Helena, Johannas, Margrietze, David. m. 2) 20 Dec 1717, Dirckje Smit. 8 children.(No. 7 was Jacob b. 1722.
I assume you know where you fit in from here. I know there is also info that goes back in the Netherlands...but she only provided me with the family in America.
She is sending me (in the mail) some info provided by another Dutcher researcher who did this research about 20 years ago...When I receive it, I will see if there is any more specific info regarding the maternal line. But I think we can rest easy that this is a fairly reliable source. If you want to discuss it further, feel free to contact me. Heather Dutcher-Ross