you can get a verizon inpulse pre-paid phone, but its at least $30/month for that. ($1/day, unlim verizon to verizon, and unlimited nights)

next step up is easypay, which is basically having a plan without a contract... its $50/month for 350 mins, or $70/month for 700. unlim verizon to verizon, 3000 nights and weekends. no contract.

sounds like the best option for her would be something like virgin mobile, which allows you to pay as little as $20/90 days and wouldbe best for emergencies. also- if you put $100 on the virgin mobile account, it keeps it active for an entire year, so assuming she'd only be using it for emergencies, that would be the best option.

just stay away from boost mobile.