Have you heard of a book that came out in 2001 "Shepherd In The Wilderness" Peter Hobart 1604 - 1679 by Edward Franklin Riley. University Press of America, Inc.
He states that through new research Rebecca Ibrook was not Peter's second wife.It was Rebecca Peck.In the book he give his sources.I purchased it through Barnes & Noble and I should think there is information of it online.
It is a very interesting book and is now being used in Universities thoughout the nation.She was the neice of Rev. Robert Peck and daughter of Joseph Peck and Rebecca Clark.
Just thought I would mention it, as most all of us descending from this line have thought he married Elizabeth's younger sister.