I may have found it, or at the very least, a workaround.
It was completely off. Once in there and turned on, I set "require password" to "immediately". There is also a "15 minutes" setting instead of immediately, but I'm not rich enough to try that setting and keep buying things to see if it worked
My son checked his iTunes account & found out that that his 4 yr old daughter had $158.82 in app purchases.
Whoa! He really needs to enable restrictions on his device especially for in-app purchases. Because my youngest son play a lot of games and watch cartoons via Netflix on my iPad, I have restrictions enabled before instance, he cannot make any in-app purchases, he cannot delete any apps & he cannot purchase any apps.