Right now, Spotify currently only supports Spotify Kids through the dedicated application and it's not currently accessible through devices such as Alexa and Google Home. I'd recommend if you wish to potentially get this on Spotify's radar for future changes then you can create an idea in the Idea Exchange. You'll be able to find out how this all works in this handy Spotify Answer here.
Have an awesome weekend,
EthanS1Rock Star 16
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