In most cases parents are happy with “self defence theatre” in which the parent feels they’ve done the right thing, in which the child feels confidence because they falsely believe they can defend themselves.
Most parents I think would be reluctant to have their children really learn to fight/defend themselves.
When parents tell me their kids are doing karate, and if they are interested in my thoughts, then I ask them, “exactly why are they doing karate? Do you know? What’s your true goal?”
And if their real, true goal is self defence then I gently explain there’s better options than karate.
I teach my girls to fight.
My intention is 1. to keep them out of fights 2. to make sure they can escape or win any fight someone else forces upon them.
Play dumb, hide your worries, try to talk yourself out, if it doesn't work hit, grab and twist or kick with the intent to cause severe pain. Then shout and run.
An armed society is a polite society and I do my part.
If an assailant get hurt I can live with that. The bloke I gave a beating some 25 years or so ago actually became a better person as far as I could se.
The value of "martial" art training is that it gets over the surprise factor.
Dealing with a stranger being in your personal space, grappling with you, pushing you over, and/or hitting you: you don't want an actual attack to be the first time your child experiences any of those.
If the child is somewhat used to those things, she has a chance of thinking clearly enough to make herself a chance to run away. Otherwise the third "F" reflex, freeze, will take over.
Everything else you do in a fight should just be in order to get to this step.
It is unclear to me however if anything I wrote contradict it or if you just wanted to stress it.
But do you really* want your child to learn to "win a fight" or to "fight"? To what degree? Any fight whatsoever? Doing so would require teaching things (s)he does not fully understand and are emotionally unprepared for, e.g., maiming or killing someone. [OTOH if you want to teach that to a child, then teach him how to be a doctor b/c doctors know how the human body works better than almost anyone else and how best to turn it off.]
Instead set other goals: self-confidence, pride, athletic skill and endurance. I would first explain the role MA plays and constantly emphasize avoidance of hostile situations. IMO teaching anyone (including children) good evasion/escape is more useful than MA and more fun.