Same for my wife. She’s been using a 2006 Macbook for years, works fine but she was complaining that she can’t access the new features that are in the newer machines OSX (Yosemite/El Capitan) that our relatives use like sharing of photos and movies (instant shared streaming from their iCloud accounts that I get on my Mac Mini). Older machines are limited to Mountain Lion or thereabouts. I recently replaced it with a new Macbook Pro for her use, and she is happy once more. Interestingly, the 2006 is faster what with the SSD solid state drive I have in it, compared to the new machine. I’ll upgrade to SSD later on for the newer machine, best way to make it fast. Meanwhile, the 2006 Macbook is now being used for my workshop driving a 3D printer or playing movies.
One feature my husband likes is iWeb (Leopard or something). Apple dropped tech support for it, and he was told iWeb won’t transfer to the newer models.