By "take advantage", you mean offering her a direct path into her intended career.
As for how much I'm planning to pay her when we can get funded: I was planning on $30k salary. Per indeed.com, "entry level graphic designer minneapolis" is $31k. At the national level, that number can go as high as $50k, but frankly, she doesn't have the skills (yet) to get a $50k job. After a couple of years, she will.
So just based on what you've said in this comment, you're giving her the choice of either working for a small percentage of 0 ("equity") or she can wait until you have the money. Should you ever get the money, you're going to pay her just under market for an entry-level job. If you don't get money for 2 years, she's clearly no longer entry-level, you've gotten years of work from an impressionable young girl for free, and you're going to do her the favor of paying below-market wages.
Maybe your intentions are good and it's just the execution that is piss poor, but judging on the comments on this post you are seriously taking this girl for a ride and you should be ashamed of yourself.
> she instinctively understands the value of giving 100% as a measure of self-worth.
Instead of money, of course. She's not worth that.
> she has no education beyond high school
Completely irrelevant.
> when her skills are rounded out and the money is there, I'll pay her going rate, and glady.
No, you won't. There will always be one more skill she lacks and there will always be one more thing you need to buy "for the company" (but use yourself, of course, because it's your company).