If you go to the Garrett forum, you will see there messages from a Carol Garrett. She is a researcher, perhaps professionally, of the Garrett line and she has come to a conclusion about from what line Margaret Foote descends. I have not yet entered her information into my database and right now cannot remember it or find it. Do try to contact her on that forum and perhaps you and she can find some common link.
I assume your wife and I are relations - I'd like to know how she is descended.