Please take this as good advice for you, but mostly for your foal.
Young horses should never be raised alone, even by the most experienced horse people. They truly need other horses to learn about what they can and can't do.
If you haven't go see the movie BUCK. Its about a horse trainer who has to deal with a young horse, around 5 or so, who was raised for the most part alone. The horse did not respect humans, and in the end had to be euthanized. He could not be corrected.
Please send him in with another foal or two, or even with some other adult horses.
What you do now with him, may come back to haunt you. Horses are much more complex, and well, this just seems like it could end up very badly.
She sure is a cutie and looks beautiful. I hope you take the suggestions some folks gave you here. The comments of how cute, sweet, etc are not going to help you when this horse begins to develop.
On so many levels, I just cannot begin to tell you how bad this could turn out.
Horses are herd animals by nature. Yes, some horses can do well on their own, but mostly those are older horses who grew up with other horses, not foals.
I see that you have been reading about horses, thats great. I am sure you will read about how difficult it is to raise a young weanling, both for health reasons as well as behaviour development.
I have had horses for over 45 years, and would never consider raising just one. Way too many things can go wrong.
Please heed the advice from those of us who are advising you to get another horse, put this in with another foal or horse, get a trainer, etc.
Otherwise, this foal may not have the life you envision.