What music player works with a smart plug for a wake-up alarm?

You could consider using an old cassette or record player; they can be pretty reliable for this kind of setup.

If you're open to alternatives, an Echo Dot is quite affordable and can set alarms that play music from streaming services. It has a switch to disable the mic, so it behaves more like a traditional speaker without the risk of your daughter changing settings.

Alarm clock radios have been around forever, and there are even alarm clock CD players and MP3 players designed for this purpose. They might be a straightforward choice for you.

Any basic Bluetooth or Wi-Fi music player or speaker could work if it has a feature to resume playback after losing power. Just double-check that it supports auto-play, since not all devices do.

The downside with many music players is they usually have electronic switches that won’t stay powered on when disconnected. You'll want something with a physical power switch, like an old radio or cassette player.

Modern alarm clocks often come with features that let you stream music or play from a USB stick or memory card. There are also many simple MP3 players available that have built-in alarm functions, which could work for your needs.