Hmm, it's a tricky one. It's a very short time and it's not very clear what the purpose of the session is. Is it a session to inspire them to consider a career in the law (and inform their subject choices) or is it a fun 'life skills' type workshop?
If its purpose is to get them thinking about how law affects every aspect of our lives, how it raises and deals with really knotty issues and how interesting being a lawyer might be, then perhaps a relevant scenario might help. They could then discuss/decide/vote on the issues.
There's something along these lines in the intro to a book 'What about Law' written for prospective law students. Sorry, can't do a link here but the scenario is something like this....
A teenage party held by 17 year old 'Laura' while her parents are away for the weekend. It gets out of hand. All sorts of interesting questions for lawyers.
Property in the house is badly damaged or stolen. Obviously criminal behaviour but what if the perpetrators can't be identified. Can guests be forced to give evidence? Can they get into trouble if they don't name names?
An invited guest Sam trips on a loose paving stone on the patio and is seriously injured. Laura's parents knew it was dangerous and had been meaning to get it fixed. Can Sam sue them for compensation? What if Laura's parents had expressly forbidden her to have a party? What if Sam was drunk and messing about? What if Sam was a gatecrasher?
The police raid the party and find illegal drugs. Is it illegal to take these drugs? To share them? To supply them to friends? Should it be illegal to do any of those things?
Is Laura (only 17) legally responsible for any of this? What if she spent all night cowering in her bedroom, too terrified to do anything? Are her parents responsible even though they weren't there and are appalled by the chaos when they get home?
Not sure how you would make this into a more interactive/fun activity (I'm a lawyer not a teacher
) but sure there are ways! If you think it has potential it'd be worth looking up the book online and reading the party scenario in full on the 'Look Inside' function. It has a lot more detail and questions to consider.