Call records can be manually deleted from the device, but the call history will be on the billing record. Most likely, she's deleting the call history manually; no special hacks are required.
That's what im talking about. They're not even showing up on the billing record. Paid my bill online last night and decided I'd look over the records while I was at it. Would assume it was just calls taken on wifi at her office, but two or three calls were in her car, Where there's no wifi and, I would think, no way to make/receive calls without a chargeable/recordable cell service call occurring. Weird.
H53/W51, R-ing 4/'18
"Do not arouse or awaken love until it so desires"-Sg.of Sg 2:7
"So oftentimes it happens,that we live our lives in chains, & we never even know we have the key"-Eagles III 1:3