Hi Halee77,
Thanks for posting your question here. There is one issue that comes to mind which might explain how your sister's listing descriptions got changed to HTML code when she posted them through Auctiva, although I cannot really verify whether that was the culprit here.
If you are using the older version of our description editor and you use the "Back" button on your browser to go back to the listing creation page after leaving that page, it will cause the description within the editor to get switched to HTML.
If that may have been what happened here, she should be able to avoid encountering the same problem moving forward by adjusting her work flow such that she no longer uses the browser's "Back" button to get back to the listing creation page or by adjusting her account to use our newer editor.
If she would like to set up her account to use our newer editor which does not exhibit this behavior, she can do so by mousing over the "My Account" tab, selecting the "Acct Preferences" option under "Settings", checking the box next to "Use Design Editor v2.0", and then clicking the "Update Account Preferences" button below.
I hope this helps. If she needs any further assistance with her account, please feel free to have her contact our customer support team by mousing over the "Help" tab on our site and selecting the "File Support Case" option.
-Mike