Hi Kathryn,
You've reached the right place for help. I'd be happy to take a look at why the sales tax line isn't printing.
When was the last time you cleared cache and cookies on your browser? Doing this will help fix most issues the site may be having. I encourage you to clear cache and cookies by following this article.
https://community.intuit.com/articles/1771580
Give this a try and let me know happens when you print the invoice. I'll be here to help.