Apple products and the Apple OS (currently based upon BSD) are 
proprietary.  If one needs service (hardware or software), one 
effectively must use an Apple store (at least in the USA).  The 
colleague is retired and has little money (this is the downward mobile 
USA economy save for the neo-liberal profiteers).  She got a used/refurb 
Lenovo Carbon X1 and I just installed a working Linux on it -- 
everything worked "out of the box".

Reading more, Timeshift appears to be a systems, not end user files, 
backup utility.  Any suggestions from anyone?

Take care.  Stay safe.

On 8/8/21 7:32 PM, Konstantin Olchanski wrote:
> On Sun, Aug 08, 2021 at 04:09:04PM -0700, Yasha Karant wrote:
>>
>> Assuming that she obtains a, say 1 Tbyte, external USB drive
>> (powered from the USB port and either mechanical or SSD), she plans
>> to do incremental backups to the backup drive.
>>
>> ... what ... would anyone recommend?
>> ... [need] tool [that] actually "works".
>>
> 
> get a mac and use the built-in incremental backup tool called "time machine".
> 
> spend more $$$, save on time, headache medicines and torn hair repair (assuming you still had any).
>