We understand how important it is to manage your data usage and service each month. With 5 lines using data and only one using the majority, it is best to manage it so everyone on the account has enough to use. With regard to limiting the data usage, you can do so by adding our Verizon Smart Family service. Here is a link which provides additional information on this service https://www.verizonwireless.com/support/verizon-smart-family-faqs/#verizon-smart-family. Please let us know if you have any additional questions regarding this service.