The YouTube channel "People Make Games" has a couple of reports that I'd suggest parents consider watching first before going down that road:

* "Investigation: How Roblox Is Exploiting Young Game Developers": https://www.youtube.com/watch?v=_gXlauRB1EQ

* "Roblox Pressured Us to Delete Our Video. So We Dug Deeper.": https://www.youtube.com/watch?v=vTMF6xEiAaY