Hiya Rya!
Welcome to planDisney! Your 12-year-old sounds like a thrill seeker looking to enjoy some excellent attractions. I recently have had to deal with a similar issue as my son who is 10 did not want to ride any thrill rides but my 7-year-old did. It placed us in a predicament as I had to consider leaving him behind.
Now, according to
Walt Disney World Property Rules, a child 7 years and older can board an attraction unaccompanied. You will have to consider if your 12-year-old is mature enough and willing to join the queue for these attractions on their own. I felt comfortable leaving my son while we boarded a thrill ride but we left him with my cell phone and kept in communication with him while we waited to board so we knew he was ok.
On some rides where you enter via the Standby queue, you will be able to stay together until you get to the end and then can separate from your son. Just speak with a Cast Member about how you can do that and they will assist you. However, other rides where you will need a
Lightning Lane Multi Pass, Lightning Lane Single Pass, or a spot on the
Virtual Queue will require that everyone joining the queue have it.
TRON Lightcycle / Run is an attraction you can only enjoy if you have a spot on the Virtual Queue or if you purchase a Lightning Lane Single Pass and will be an example of an attraction where if you were to join your son then everyone will have to pay to join him.
Expedition Everest - Legend of the Forbidden Mountain has a Standby queue so consider this the attraction where everyone can join together.
You can also consider
Rider Switch. For this to work you will need two adults where one can escort your 12-year-old onto the ride while the other adult will stay behind with the rest of the group. Everyone who joins the Lightning Lane queue will need to have a paid pass in place. This could mean you spend less as only two people will need to pay for Lightning Lane access.
You have some decisions to make and will maybe need to have a conversation with your family. If they are nervous consider watching some ride point-of-view videos so they can see what the queue and the attraction will be like. This has helped my anxious son try new experiences and find out that they were fun!
I hope this helps and you have a great time!
Happy Planning!
-Nimmy