Really well shot and an original idea for a school team with such a dynamic genre. Dani dying and coming back to life was a great narrative device, and while you got a bit of mileage out of it, I would have liked to have seen it only go bigger and grander, as it stands it just kind of fizzles out. Still, there's a clear understanding of story structure here, with her deaths relating to her brother's anxiety- and they kind of learn to solve both their problems together- I would have liked to have seen more chemistry between the brother and sister, as this is a seldom seen dynamic in 48Hours and sibling bonding could be really touching.
I'm in the "why does this have a laugh track?" camp, I hate laugh tracks at the best of times, and I really wish you guys hadn't included it in this film, because it only took it's quality down. It feels like it was decided on in the edit, and the original vision for the film just played out normally? I'm making an uninformed guess that maybe the editor wasn't confident enough in the jokes and thought they could zhush them up a bit- but the jokes were great on their own! The laughs and awws felt like they were pretty pointlessly inserted whenever there was a break in the audio.
Keep plowing away, I could easily see you guys as regular finalists in a few years. Work on your technical side a little more, and make stories with larger stakes which go bigger and deeper.
As for your title, "Don't Die Danni" is great, it's provocative and gets me interested in what the story could be. Nice bit of alliteration (or assonance...?) to boot.