Yeah as long as your primary blog is not in that same folder you'll be fine.
Take a look at the server path when you select http://jetcopywriting. It should be something like this:
Server Path: /home1/ROOTDOMAIN/public_html/JETCOPYWRITING/
This is the folder where WordPress will be installed. So if your other blog is in the root folder or another folder, you'll be fine.
Hope that helps.