Who decided kids don't deserve a real shoulder rest?
There are plenty of kid-sized shoulder rests. If you buy your violin from Montchanin Mountain Music, you will go home with one that fits your instrument. (Well, not if you choose a cello.)
If the kid still wants to play with a sponge that may have been used to clean up spaghetti and dog messes, that's fine with me as long as it is a choice, i.e. to play the instrument with a ideal bacterial growth medium touching their body.
What could possibly go wrong with buying fiddles online sight unseen?
The descriptions can be a little hard to understand...here's one I found online:
The strings are correctly spaced, and the throat is extremely comfortable. It comes filled with a high-end carbon dietary fiber violin bow, a high quality Oblong lightweight violin situation…..It comes down with a brand new metal training mute and a superior neck sleep.