Hi Joyce,
Do either computers have CD or DVD burners? You can copy files from one computer to the other pretty easily this way. You can also go into the Documents folder on the old machine, and copy the games folder. This holds all of your grand ma's saved games, so any preferences she's created, or progressed made during game play will also be transfered to the new machine.
If neither computer has these functions you have a few options still. Take these programs from the old computer and put them in a 'Zip File"-- zips are compression programs that make large files smaller so they they transfered to where ever. Once this is done, email the programs to yourself, and open and download them onto the new computer.
You can also go out and buy (40 - 75 bucks) an external CD Burner. Put this new software, and hardware on the old computer, and then perform the transfer of the desired programs.
Charles
PS: The large computer box stores typically have a section devoted to older games--usually by the check out in a bin or stand. These CDs might have any number of games on them, and the ones yo want might be on these. Also googling these compilation's CDs might yield results from some outlet from the web and at least point you in the right direction.