Linda, terminology is very important when talking about visa and entry stamp.
She asked if she will get another 30 day visa and No, she will not. Because - apart that "30 day visa" doesn't exist - she will receive a 30 day "visa exempt" stamp.
I do not think they would ask it at the Bangkok airport. Officially they could, together with a financial proof (10,000 baht) and lodging proof, every time you enter Thailand but almost NEVER ask for them. Mostly it is a document that can be asked by the embassy you are applying tourist visa at. I would daresay not to worry at all ...