I've got to say, this seems creepy to me. It's not just spying on kids, it's spying on whoever is in range. It's basically an open mic in your home, transmitting to god knows who.
So is a "smart" TV, a laptop computer, a tracker (a more appropriate name for a cell phone or mobile phone which recognizes the activity it does the most), and so many other voice-activated gadgets with network connectivity all running proprietary (read: untrustworthy by default) software. And a lot of these devices have cameras in them too, also under proprietary software control. And virtually all of them have been used by kids for years. Some of these devices have geolocation hardware in them too, that must make it easier to geotag the data the proprietors can acquire, keep, and share. I think it's great that people are finally getting around to thinking about the security and privacy implications when this is presented to them in the form of a toy but really this is far too late in coming.
Departing from the parent comment, situations like this are also a constant reminder of the profound inadequacies of modern-day IT experts who choose to surround themselves with these things, not in an experimental way to investigate them but as consumers who apparently value minor convenience more than their own privacy.
Only software freedom helps you enjoy all of these devices in a way where you, the user and owner of the device, can have a real say in what gets recorded, where that data is copied, and thus who gets access to that data. It's not about shutting these things out of your life entirely, it's about respecting who should control this data.