We took her phone in to the local store (her choice, it's her phone after all) and they got her activated really quickly and easily. They wound up having to give her a new SIM card though, not sure what that was all about. But she's up and running and VERY happy with the phone. I got some serious brownie points with my lady.
About her old Samsung (Galaxy Relay 4G slider), I flashed it to CM 10.2.1 (JB 4.3.1) after updating the modem and something else first and the phone is actually really quite usable. I wouldn't choose it over my X, but if something ever happens to it I wouldn't have any problems shifting over to it for a short time.