Marianne:
I personally can't be of much help to you. I've done virtually nothing with the Heavner/Hefner, etc., families in Lincoln and Gaston. Of course, I can tell you from personal experience that you need not worry too much about how Catherine's surname was spelled. It's not uncommon to find varying spellings for the same person. The clerks who filled out most of the forms and ledgers in the courthouses wrote them like they heard them...or how they felt like spelling them. I've worked with lots of documents from the 1800's and spelling is anything but consistent for most names. Even in the twentieth century, I found three sisters' marriage records in Burke County with the surname spelled differently for each of them. You might check some of the folks who reply to these forums, as some of them do live in Gaston county. Good luck to you.