How can I block my daughter from going over data usage?
go here https://my.verizonwireless.com/vzw/nos/safeguards/SafeguardProductDetails.action?productName=familybase&intcmp=SearchBanner:family
See a dashboard of your kid(s) wireless usage. Know when and how your kid uses their phone. Set controls or limits on data, voice and messaging usage.
hit like button if thats what you need
You can also switch to the newer Verizon Plan and add safety feature so your account won't get overage charges but rather slows down data to the next billing cycle starts. Free with XXL or XL plans, $5 for lower amounts. This doesn't just slow down 1 line, but is to protect the whole account.