Depending on how it is approached it could be, but you also don't want to put it in her mind that she can do whatever she wants and he's always there to bail them out. I know too many people with a 'he handles the money and she handles the spending' attitude where one of the spouses doesn't know/understand/care about their financial situation and expects the other one to just run damage control behind them.

I had a buddy whose wife used the last of their savings(all his earnings, she was long term unemployed since before they got engaged) to buy a car while he was at work without discussing it with him and then over drew their debit account before he got his first paycheck at his new job. Both instances were within a month of each other. She claimed she didn't know she was putting them in a bad spot either time because she didn't realize it was the last of their savings.

Definitely don't punish her like a child, but imo that is a serious problem and she should be forced to at least sit down and address it from a numbers standpoint.