MTB is another shared ancestor of R. and I! but we do not share her spouse: he is descended from the Pauli Vanderbee(c)k and I am descended from William Bennet. I'll need to poke at this for a while to be sure. Around the same time frame as Anneke Jans, so probably this will not change the number of generations involved.
ETA: She is improbable but well documented.