You can use your wife's USB ports with a USB CD-ROM drive to rip, and if that computer will be on all the time then ripping to an internal or external hard disk and sharing the files from that computer using SMB should work.
If you don't want to depend on your wife's computer running all the time, then a NAS is convenient. Synology and QNAP are popular NAS brands, and they have some compact relatively inexpensive units.
In that case, use your wife's computer with a USB CD-ROM drive to rip onto the NAS file share, and then access the same file share from Sonos. This way you just leave the NAS running all the time, independent of whatever work your wife needs to do on her computer.
If you don't want to depend on your wife's computer running all the time, then a NAS is convenient. Synology and QNAP are popular NAS brands, and they have some compact relatively inexpensive units.
In that case, use your wife's computer with a USB CD-ROM drive to rip onto the NAS file share, and then access the same file share from Sonos. This way you just leave the NAS running all the time, independent of whatever work your wife needs to do on her computer.