Here are a few things to know when searching.
2018 was a transition year so both the older JK style and the newer JL were produced.
In Jeep speak, Unlimited means 4 doors
The Rubicon is the only model with both front and rear locking axles and the JL has an electronic swaybar disconnect.
Not stuff that a HS girl is going to care about.
As far as the engines are concerned, I've driven all 3 (not counting the Diesel).
- The 2.0L Turbo 4 cyl is great in straight line acceleration and the turbo lag isn't really noticable
- The 2.0L Turbo 4xe with the plug-in hybrid is really good in straight line acceleration but the electric only portion is relatively useless as it only provides about 20 miles of range. It does provide a nice acceleration boost while it lasts. Takes a few hours to charge. In my experience, it might help your fuel economy by maybe 2 mpg.
- The 3.6L V6 is what I have and it's great. I'm approaching 70,000 miles and haven't had any engine problems at all. Drivetrain is a different story.
For me, the biggest adjustment was getting used to the 8spd automatic transmission. It took a long time for me to get used to that. And one valuable piece of information I've started using is to put it in Manual shift mode when descending hills offroad. Thanks to jetpilot86 for that tip.
Obviously there are tons of aftermarket modifications you can make to Jeeps and a huge community of enthusiasts. Once you start driving a Wrangler, you become part of an informal club. And there are plenty of formal clubs out there that you can affiliate with.
I've driven my Jeep between California and Texas several times and most recent long trip was Nashville, TN to Galveston. I'm 6'3" and frankly, I find it to be borderline unbearable on long road trips. It's probably better if you're shorter. Around town, it's great but my threshold for switching from enjoyable to tedious is about 50 miles. If I know I have a long road trip and I'm not going to need my Jeep, I prefer to drive my 1999 Ford Expedition due to ride quality.
I really don't recommend getting this vehicle for a HS aged kid but a girl probably isn't going to do as much stupid stuff with it as a boy and his dumb friends would get into.
Since you mentioned safety, one thing I noticed when I rented a 2024 Wrangler JLU Sahara 4xe recently was the front head side airbags. My 2020 JLUR doesn't have those.