Lao Visa Run Question (Vientiane)

Greetings!

My wife and I are in Vientiane and our 30 day tourist visa is about to expire. We were going to do a border run to get a new Lao visa, but we were unsure if she had to purchase a Thai visa on arrival (she's from a country that does not have a Thai visa exemption) during this process. We were just hoping to turn around at the border and not actually enter Thailand.

Thanks!

Eugene