Like I said, it does sound reasonable but apparently it does add up. From the link:

"[Laura] Bush wrote that a bill came monthly, itemizing everything she and her family owed, including food, dry cleaning and hourly wages for waiters and cleanup crews at private parties."

"There were some costs that I was not prepared for," Bush wrote. "I was amazed by the sheer number of designer clothes that I was expected to buy, like the women before me, to meet the expectations for a first lady."