My mom has purchased an iPhone for the first time, she chose a plan that was without any data (on purpose). She was told to get the data-block add-on so that there would be no way for her to accidentally use data. But that add-on prevented her from being able to receive picture texts from non-iPhone users. Thus, I have disabled the add-on. However now I'm concerned about her being charged for data usage. If she is to accidentally click on the Facebook app or try to check her email, or anything else of this sort, when she does not have a wi-fi connection, will it just use data right then and there and then cost her later? This is unsettling to me. Any clarity would be highly appreciated.