My mom has a 2014 Mac Book Pro, currently running High Sierra 10.13.6 with a 250 GB HDD. We're trying to clear some space, which was at around 244 GB used. So far, we've 'removed' about 100 GB of files (iTunes library, mostly). However, the used space is still at around 244 GB. We tried using OmniDiskSweeper to account for all that space. However, it only shows 57.1 GB of files. I'm at my wit's end for how to account for the remaining data ?