The person who can really help you is Myron Terwilliger. He has posted on another message here about Almira Amanda Terwilliger. He co-authored the book Terwilliger Family in American.
I am also a descendant of Johannes Terwilliger and Catheryn Heypes/Heyps through their son Dirk.
I received this information from Myron. Johannes was b. about 1690 and is the s/o an unknown Terwilliger, for my records I listed him as another Johannes. This person is the son of Dirk Evertson Terwilliger b. abt 1650. Original searchers were mistaken when they listed this child as female. Then all of a sudden too many Terwilligers started showing up in Albany County that could not be tied into Jan Everstson Terwilliger and Sytie Van Etten who were married 23 April 1685. Dirk Everston Terwilliger is John Evertson Terwilliger's brother and they are the son's of Evert Dirkson. (This was before the surname Terwilliger was taken, and when the father's names were used. I have the children of Johannes Terwilliger and Catheryn Heypes as: Margite b. 1718, Alida b. 1720, Phillip b. 1721, Maria b. 1724 and Dirk b. April 1726. I have the Children of Dirk Terwilliger and Sarah LeRoy/Larraway as: Catherine b. 1756, Simon b.1760(my line), Jannetje b. 1763, Johannes b. 1769 and Johannes b. 1775. (This probably means that the first Johannes b. 1769 died, but I'm not sure.) From which child do you descend? I'm interested in all Terwilligers too.Feel free to email me directly.