Yes, I too have done some more work on the parents of Susannah Alexander as I also have Alexander descendants from Irvine. I will need to look it out, I have a lot of notes on Ayrshire Strachan's. I think there was a connection with Reids in Kilwinning, was John Alexander and Christian Reid's marriage, also recorded in Kilwinning? which is very close to Irvine, and I think Susannah had a brother or uncle Charles, perhaps both.
Good to hear from you