Personally I would recycle the device at one of the periodic electronics recycling events, mom2. No matter how well you think you scrub a hard drive, a skilled person could conceivably glean all sorts of personal information from the machine.
Deleting files does not make the information disappear; this just erases the location information of the data. It appears to be "gone" to the operating system, but all of the data is still there and it can can be recovered by knowledgeable hackers.
I would be leery of letting a family member using my old laptop, let alone a complete stranger, unless I removed the hard drive or used data destruction software. Of course, then the computer would be useless without the backup operating system and software disks to reload programs.