Most likely that is the correct one even though she is listed as Isabella everywhere else. In my family an elizabeth could be listed as Betty, liza, elspet, lizzie, eliz. Isabella can be listed as bella, bell, isobel, isabella, isobella. So you can never tell what you forefathers names were during all the years they were around. My great granny was born Hellin, was called Nellie and her headstone reads Ellen!!!! Go figure.
Jackie
I don't know much about the Dumfries area but try and see if there is a genealogical site for that area that helps ones out. Also see if you can get copies of the church records, some genealogical societies have these published and you can get them sent to you for a fee. i found it was worth it for my family getting the information through the Aberdeen Family history.