This may be overkill, but consider a used Squeezebox Radio and setting up Lyrion Music Server on your network. It uses your music library, along with optional web radio and streaming services. You can control any device from any computer in your network. The SB Radio has a great sound, even 15 years later. It has physical buttons so your kids can choose music without phone/computer. You can get a used Radio for like $30-$40 on eBay, and Lyrion is free and open source