I used to work in this industry many years.
You can't really look at it like that. It's incredibly hard becoming a actor, pop star, professional athlete, dancer, model, presenter... It's uber competitive, most people don't make it, once you start auditioning for paid work, initially pay is very low so you'll be working in cafes etc. Of course it's different if you're a Beckham etc... But hear me out.
Auditions are experiences. It's also how you build your network, how people see you're persistent and someone might see that you're actually talented. So you can't not go to auditions because 'not going to get it anyway'. It toughens you up, you learn what to do better for next time. Most times you will not be picked, that's the reality of it.
In fact, 9/10 you won't be picked, doesn't matter why. So if you're approaching it with going there to be chosen, it will be very disappointing most of the time. Trying to be on stage is basically a lesson in disappointment and rejection, which in itself can be a useful lesson. It's not like school exams where if you work hard, you do well. You can be amazing and work so hard, and it gives you an edge over others, but usually you still won't be picked.
Therefore you can only do it if you really, really love it. Passion and love for the craft, the desire to become better and learn from the experiences, and see being chosen as a nice bonus is the only way to get through it.
Being chosen is based on connections but you can also make connections, be a pleasure to work with, super punctual and reliable, good attitude. As you say, at the local level it's a small pond, so if your DC is good and keeps showing up, people will start remembering her. And while it's harder without, look at someone like Ambika Mod.
You do it for the love and accept rejection therapy as a side dish. If you are no longer having fun and it's affecting you negatively, you get out.
If you start telling your DC early that all you need is connections, she'll easily lose the love for the craft, and potentially become quite disillusioned with trying anything in life.
You miss 100% if the shots you don't take 😉
You might like this, it's about children in a hyper competitive enviornment and how they are built up, knowing that 99% aren't going to make it: https://learning.coachesvoice.com/cv/nick-cox-manchester-united-academy-director-interview/