Happy to suggest. TY for the acorn!
When my kids were young enough to put non-food objects in their mouths, I put plants up high, out of reach. The soil could just as likely be the thing that gets put in mouth, as any plant part, which could have fertilizer in/on it, and swallowed perlite particles could cause gastrointestinal distress or damage. A knocked-over plant makes a mess, whether put in mouth or not. Teaching not to put non-food items in mouth is a good lesson, some kinds learn more quickly than others.
In the case of Syngonium, the sap can cause a rash similar to poison ivy if one has skin that is sensitive to it. It has irritating alkaloids, as so many house plants do.
Good luck with plant(s) & kids!