Safe Sense is Oculus, now Meta's official solution to this exact problem. This might be found in the experimental settings based on when you are reading this. Space Sense will cause faint ghostly outlines of objects that the tracking cameras see. It can be disorienting, but it definitely does what it says on the tin. Thanks to the unknown variable of both, it is impossible to really be confident they are safe. However, suppose they are old enough to be left alone or under another adult's supervision. In that case, having them out of the room is your safest bet. Also, having the door closed will give you an audible response if someone enters the room.  Otherwise, a means of grounding yourself, in reality, can be one of the most vital steps to a safe Vr space. Consider investing in a Vr Mat or portable fan. They can be incredibly helpful in keeping yourself pointed in a direction that is designated the danger zone at all times.