You can use it for the additional activity info. Not a full blown resume. But some concise bullets with information. For example, if you have some top individual performances in an activity, or some accomplishment as part of the activity. For example, my kid’s small project team at an engineering camp solved a problem
that other teams had failed on for several summers previously. She put that in a bullet in the additional info section.
I would not put info on family situations or things like health issues in there. Discuss with your GC, see if it makes sense to put in their recommendation. The GC likely will keep it generic and protect your privacy. If it is too sensitive to discuss with your GC, don’t write an essay about it. Essays are not therapy sessions or places to make excuses. You want to give admissions reasons to bring you to campus.