Should I send my 5yo girl to preschool?

Hi Twin Stuff community.
Well, this question isn't related to my twins, but their older sister. However, I'm still wondering about this and would like to have some opinions from other people.

So, here's my concern :
My little girl, Stella, will turn to 5 in almost 2 weeks. And she's my second child.
She always had a strong personality and caused us many problems. It's way different and more difficult to raise her than her older brother at the same age.
At the beginning we managed to deal with it, but as time passed things went worse and worse about her.
She spend many of her time yelling, crying and making tantrums. If we try to talk to her, telling her to calm down, she doesn't listen at us or argues. If we start to scold her then, she's insolent to us, she argues even more, yells at us, and even try to beat us.
We have baby safety gates on stairs at our home that she still can't always manage to open by herself. When she's by a side and us by the other, if she can't open it she screams behind the gate, she hits it violently, shakes it and try to force her way through it. If the gate is open or she manages to open it she came at us, she yells, pushes us, insistently loudly speak to us even if we're doing something else, etc...
With her siblings she's not better. If they're in her way or too close to her by her own judgement she gets angry and start yelling at them. It can happen she plays with them but it's pretty rare. When we take care of the others she always try to come in the way too and get the attention to her.
When we're outside it like a disaster too. At a time I even was really anxious to take her outside. She listens to absolutely nothing, she just runs everywhere in any sens, she crosses the street without paying attention of what is happening around her, when we cross by other people she bother them and makes fuss, she's mad with other kids too.
Even so, there's few positive points. During lunch time she's totally calm and doesn't make any fuss. At some rare time, when she's in a good mood, she adorable, she listen to us, and tries her best to remain calm and do what we want her to do. And then, when she's alone with us she's a real angel.
Also, I think that since last year she tends to become a bit calmer throughout the year and acquired a better behavior, but still this is far away from being enough.

This said, around us, some people are judging my husband and me to not send her to school. They say her behavior is because of us trying to keep her locked inside the family environment and that she's going to have mental issues later.
Now, let's explain our choice and point of view :
First, school system. We're living in Sweden, here kids from 1 to 5 can go at preschool, but this isn't compulsory. Compulsory classes start at 6 yo with preschool class (this is in fact the last year of preschool in here, and so, the only year of preschool that is compulsory), and is then followed by primary and lover secondary education from 7 to 15 yo. So, since preschool isn't compulsory, why would I had to send her there? Only for society fitting? Some would say preschool help children to get accustomed to school before to start serious things at primary school, but in here the first compulsory class is still part of the preschool and then is made to follow the purpose of preparing child for primary school.
Second point, I'm Russian, and in Russian culture mothers try to keep they child with them as long as possible. In Russia it's frowned upon and see as a betrayal against the child for a mother to sends her own child in nursery or early at kindergarten (except for those who really have no choice of course). This doesn't mean we keep treat our child as babies for years, in fact I think that Russian kids are more free and earlier than many kids in other countries. Then, without regarding my cultural thoughts, I'm also an housewife, and so, I don't see the purpose of sending my kids early in preschool while I'm at home to take care of them.
I kept my eldest son, who's 7 yo by now, at home until his 6 yo and that he started compulsory classes. He's totally fine and never turned bad because of this. So I think Stella not going to school by now isn't the real matter then.

Even so, I though about this and I'm a bit more open about sending her in preschool, although I'm still doubting.
Mostly because we're afraid of how she can be somewhere else and with other people, so we keep her with us as much as possible. When we send the kids to their grandparents as exemple, we always send them appart (Stella alone, and the others together) if we're not going there with them. So we're afraid on what will be her behavior at school, and I'm also afraid of how would others will act with her.

What do you think about this?
Do you have any tips to help us raising our daughter a better way?
What are your thoughts about the preschool fact? Should I try to send her to preschool for in next september? Or stay on my first plan and wait until compulsory class, a year later?

Sorry for this long text, and thanks to those who had read me until here.
Yeli

 

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