Some MiFi models will act like a USB to Ethernet adapter when plugged into a computer. Next time she gets 0 throughput with WiFi, give this a shot. If nothing else it will definitively rule Verizon out and let her get work done. It might also be worthwhile to upgrade to a MiFi model that can support 5GHz (for example, the 6620L); 2.4GHz can be extremely crowded depending on the property.