Firstly, she's not being 'bratty'. She is 'disrespectful' to you because you obviously haven't *earned* her respect yet(not judging you at all). Perhaps you haven't yet taught her her 'manners', but even so, if you put a horse into a too stressful, confrontational situation, they generally get 'right brained' to some degree & stop thinking & just react - including running people over for eg. She's just being a horse.
To different degrees they are all nervous of different people, places, things they haven't become accustomed to. If she were a new baby, it can be easy to introduce them to all sorts of stuff, but the older they get without this education, the more they're likely to be stressed & reactive in different situations. They are also herd animals who need to be in the company of a good, trusted leader to feel safe. If she's a year old & hasn't yet done much regarding the above, I'd expect to need to go extra slowly & patiently & expect it to take a HEAP of repetitions for her behaviuor/attitude to become reliable.
So, for a start, I would only play with her in environments that she's comfortable for now. I would develop a good relationship and communication there first, so that you earn her respect and role as her leader, before you test it out by taking her out of her comfort zone & ask her to trust you.
I'd be doing lots of 'approach & retreat' type exercises with her, to get her gradually desensitised & confident with stuff, without being confrontational & pushing her over any proverbial cliffs. I would be using lots of positive reinforcement(rewards) to 'train' her attitude & getting her thinking playing your games is a Good Thing & worth her while.
I'd be teaching her to yield in all directions, first with direct(fingertip for eg) pressure, then with indirect(rope, stick, bodylanguage) pressure, so that you can control her with gentle pressure. I'd also be teaching her the 'manners' you expect of her - eg. 'respecting' your space, no mugging, etc.
Once she's learned all the basics & trusts you to look out for her & be a considerate & consistent leader, then I'd think it's time to get her out & about. Use approach & retreat again, to get her *gradually* better in different situations & environments, rather than putting her in 'sink or swim' type situations & overfacing her. This will reinforce her trust in you too, which will help with subsequent lessons. Again I'd be using a lot of positive reinforcement to help her develop a good attitude about these things.
Oh & being a hoofcare practitioner, I cringe at the thought of unhandled young horses, as it generally means their hoofcare has been neglected as they've developed. So if she's not already, for the sake of her health & soundness, spend time getting her great with her feet!