She will always be smaller and weaker. Letting someone heavier get you on the ground seems like a bad idea. It seems to me that being able to do serious damage and retreat rapidly makes more sense, but I am no one's expert.
I've got a daughter... and the problem is that she will be letting someone heavier and stronger get close to her and it is
THEN that the "yes, no, maybe" problem might become a real issue. I can pretend that she will be at striking distance, but that would be denying the overwhelming majority of the evidence about how sexual assaults (and physical assaults against women in general) start (not the ones that are sensationalized on the news... the much more common ones that start with isolation and betrayed trust).
This is a big issue when I teach
Women's Assault Prevention. Everyone shows up wanting to kick in the groin and palm strike the nose... that's fine if you're worried about ski-masked guys on the jogging trail, but it doesn't work so well against the co-worker leaning over you at the office on a late night, the study partner next to you on the couch or the boyfriend in the back seat who doesn't get the "stop". The Ski-Mask guys are less than 1% of reported sexual assaults.
Extreme Close quarters skills are what women and kids need.
A thumb into your eye socket while grabbing the back of your ear and grasping until your skull is being held between the thumb and index finger is just as practical for a 7 year old kid as it is for a 70 year old woman or for me or you. Knowing how to escape from being pinned to the ground so that you can get to that technique, a choke or a lamp to break over someone's head makes sense. Teaching a 50 pound kid to kick or punch is like teaching a horse to count... even if it works, they can't do much with it.
-RJP
edited to add:
I also recommend wrestling for boys in that age range for the physical reasons and most of the psychological ones.
I think that at striking distances Verbal Skills, Awareness, Avoidance and De-Escalation are much better tools to give kids than strikes. A