According to my grandfather's notes, she was Katherine Ann Birge. I could not find anyone with that name anywhere. A few years ago, a distant cousin (who has a copy of John Angleman's will) told me that John Angleman's 1st wife was, in fact, Catherine van Syckle.
My gg grandfather, Abraham, has both van Sickle & Suydam as his middle names. It makes so much more sense, to me, that his mother was van Syckle.
I've been researching my Angleman family on and off for at least 10 years. I thought it was going to be so much easier to find them, as my grandfather had a lot of handwritten notes/research. But, it has not been very easy at all. It has been fun, though.
I just recently came across your blog & enjoyed it very much!