I think poster like you are being ridiculous to be honest. I've got a 5 year old girl, and I agree with the sentiment that she should be in school, but imo I think I would be doing what OP is doing, although I'd be inclined to go into the school.
If she doesn’t feel like it she doesn’t have to go.
This is the school's failure to step in and protect her, all she has learned at this point is if she is bullied and hurt, her mum will step in.
she seemed to be standing up for herself, which is great.
No, she retaliated to ongoing UNCHECKED bullying by two boys, then got in trouble herself.
also, if she needs to learn to make good choices
She has been told to 'stay away from them', but how is that achievable in a small classroom, I'm sure she was staying perfectly away from them when they drew all over her artwork? ruined her cardigan? She wasn't playing with them when that happened? but then it's easier to get the victim to change their behaviour to not attract the attention of the bullies, what the hell is THAT teaching?
I feel like posters like you are teetering into the disgusting 'boys will be boys' category, where two boys to ganging up and bullying a lone girl because she is an easy target is wrote of as hi-jinx.. the school should be all over that, but they haven't even been arsed to contact OP, says it all really about their care and attention to student welfare.
What she should be learning is that if she is bullied, her clothes ruined, her artwork ruined and she's been hit, or she feels unsafe attending, then the school will take action to stop it. Our school is pretty hot on this sort of thing, we've had some incidents with a couple of boys doing quite nasty things to my daughter, they are never allowed to get away with it, so while she sometimes feels upset by it, she will go back knowing the teachers are there to stand up for her, THAT is what the school should be doing in OPs case and they are failing.