Panther doesn't require you to have any prior experience driving for straight trucks. My husband had his CDL A, but I had never driven before we got hired. You do have to have a permit to get set up in orientation I believe, or be getting it within 30 days. Keep in mind though, until your wife actually has her CDL B, she will not be allowed to drive the truck with their knowledge due to insurance reasons. We asked about why the ad says straight truck spouse training, and they said it was an old ad. One person told me you could train your spouse in an empty parking lot, and another said no, you can't even let them drive at all.
We ended up going home for a week so I could pay a little money to a company that let me practice in their truck with a trainer, and take the test in it. Hope this helps a little.