If the engine ingested any turbo parts, the bill isn't unreasonable... and it probably did. What usually 'cooks' a turbo is not allowing it to cool down after the engine has been running for a while. The hot side 'cokes' up and the bearings fail and it's off to the races...
My rule of thumb on all my turbocharged engines is a 3 minute cool down at idle after working the engine. always.
What you should have done when you investigated the noise earlier on, was pull the intake side hose and grab the impeller with your fingers and wiggled it. If it wiggled at that point you possibly could have saved your mom a big repair bill. All turbo's will have a little back and forth movement but should never wiggle because the clearance between the impeller and the housing is very close and when the impeller hits the housing it comes apart, hence the intercooler and injectors and sometimes a head and pistons too, depending on how big the shrapnel is.
2015 Backpack SS1500
1997 Ford 7.3 OBS 4x4 CC LB