If you want to stick with the Verizon network, look at Page Plus or Total Wireless. I switched to PP for $29/mo with 1500 minutes and 1gb which is plenty for my use. A friend has used PP for 5 years with no issues.
Since you mentioned the need for some data, TW offers 5gb for $35 or 8 gb combined for two lines for $60. Both plans have unlimited talk/text. When the +1 is ready to give up her flip phone and go to a smart phone, we'll switch to TW and the $60 plan. Both companies are owned by TracFone.
Fwiw, here is a list of MVNO's
List of MVNOs