Originally Posted by
dinoscool3
My parents who are Silver on UA have gotten Pre-check 100% of the time. However, due to TSA age requirements, those between the ages of 12 and 18 cannot go through Pre-Check (or so I have been told multiple times) so I have to go through the normal lane every time. It's very annoying for me

Those under 12 can accompany their parent, if their parent has Precheck. Anyone over 12 would need to have Precheck on their boarding pass to go through the Pre line.
As long as you get the three beeps, there should be no reason to deny you access to the Pre line.