Mac Ssd Disk Not Showing Enough Free Space

[Huderon]

My daughter has a Macbook Air running Mountain Lion, 4Gb memory and a 60Gb SSD disk.

She currently has a couple of dozen of her own files on there along with her Itunes library (not the actual MP3 files, just the library if that makes sense) and the OS on there, but the system is reporting that the disk only has 10Gb of free space.

My guess is that the SSD is misreporting the amount of free space, possibly because of the way that deletion works on SSD drives. Could this be the case, and if so how would she go about getting the thing to report the correct amount of free space ?

She is currently in Swansea and the nearest Mac store is in Cardiff, so she would rather try to sort the problem out herself if possible than do a trip to Cardiff.

[T&S]

It may be an idea to download an App from the App Store. There are several that will give definitive details on the Hard Drive and help delete them. CCleaner and Disk Doctor are both free and I use them to free up space.