Hmm, is this something like Until Dawn with less mature themes? :D If you do decide to expand the group, there's a character I'd like to use again:

Well-to-do city girl, used to luxury, has lived a comfortable, sheltered life. Sophisticated, usually pleasant, but occasionally whiny and entitled. Confident socially, but has little knowledge about camping and stumbles awkwardly with tasks related to the activity. Agreed to participate in the camping trip after much persuasion.