While a firmly agree with @Bear_Nenno about building your own kit, I would not purchase any critical medical items such as tourniquets, hemostatic gauze, pressure bandages, et cetera from Amazon. Amazon is full of counterfeit medical items and while I’ve never heard of a genuine CAT tourniquet fail in operation I’ve seen the fake ones fail just in training. The premade kits you find at REI or on Amazon are mostly useless for real traumatic injuries; if you want an actual premade trauma kit order them from North American Rescue, Dark Angel Medical, or some other specific medical supply provider which will verify their supply from legitimate manufacturers.
My truck medkit is one bag but actually has two sections inside of it; one is a trauma kit with tourniquets (two in kit plus two more in extra storage), compression bandages, a dual chest seal, small and medium compression compression bandages, heavy duty trauma shears (Leatherman Raptor with a glass-breaker), and a UV flashlight, along with several pairs of gloves for body substance isolation (BSI). The other is a “boo-boo kit” with bandages, gauze rolls, cravats, tape, OTC analgesic and anti-histamine medication, burn gel, Cavit, wound closures, antiseptic iodine, saline, sugar and electrolytes, et cetera. I also have a SAM splint, stethoscope, sphygmomanometer, penlight with pupil gauge, a couple of larger flashlights, plus a couple more chest seals and compression bandages, gloves, and eye protection to fill out the bag. I no longer carry a CPR rescue breathing mask because rescue breathing has been shown to be ineffective and wastes the rescuer’s energy, and I don’t carry sutures or an oropharyngeal airway because while I’ve been trained to use both I don’t have the certifications to use intrusive devices. This kit doubles as my expedition-grade backcountry medicine kit and so it probably has more in it than most people would consider, and my small group and solo kits eschew most of the trauma gear because if you suffer some kind of serious trauma miles away from the trailhead that requires a chest seal or CPR the odds are likely that you’re going to die before you can get evac’d, so I tend to focus on a few high value items and a bunch of quality-of-life stuff like burn gel and infection prevention over chest seals and multiple tourniquets. I don’t carry an epipen because of the cost and assume that anyone who needs it should be carrying one themselves but I always check with companions before hiking whether they need/have one or have other medical issues such as diabetes, a heart condition, et cetera, and what medications they have and want me to apply in the case that they are incapacitated.
All of that being said, none of this gear will be of much use to you without the right training. To that end, the o.p. should enroll the daughter in a Red Cross, NOLS, or WMA First Responder (not just First Aid) course, which will teach her how to both build and use her own kit. Carrying a pre-built kit with no training or time spent learning how to use the contents virtually guarantees panic when a medical emergency or even just a significant minor injury occurs, while these courses no only train to respond to a variety of medical issues but also have the students worth through scenarios where the learn to size the scene up, perform airway/breathing/circulation check, and then determine the appropriate course of action given the incident and apparent malady, i.e. check vitals, perform an exam, or take a medical history, and from there formulate a list of issues and a plan to perform interventions and/or call for medical assistance (or evac in the backcountry). Not having this training means that not only is the responder unprepared to deal with the various issues but may also not recognize a hazardous situation and run into unforeseen danger like a toxic atmosphere or an unstable overhead environment. If you have the training you can often improvise the necessary gear (another thing you’ll learn in a Wilderness First Responder course) but the best gear is all but useless without the right training. Also, the WFR/WFRR classes I’ve taken have mostly been a blast.
Stranger