Susan, I only found your post today and can only apologise. There is an Alexander Burnet (brother of Arthur and Andrew) born 1791 Crosslee, Selkirk but he died in Hawick, Roxburghshire in 1868 aged 77. I have a copy of his death certificate and one it it states he was the widower or Eliza Cranston and married to Betsy Scott. I tried to copy the certificate for you but it wouldn't let me. Have you been to Scotland yet?

Sandra (Burnett) Ritchie