Lots of good replies in this thread
But she asked for the SIMPLEST way. That's purchasing a USB turntable that does it all for you, and then you can load the files on your computer.
Certainly there are other ways, I've used my turntable from 1983 (without amps, actutally) direct into my XP computer using Audacity. Getting the settings JUST RIGHT is a pain, and editing them. I'm not very discriminating when it comes to sound quality, myself, so some of mine may sound like they came off a Victor hand-wound mono. I have no idea, I'm pretty tone deaf. I'm happy with just having the old songs in electronic format, without having to purchase something I already own from online, or having to use my turntable over and over.