Naughty 4 year old or something wrong?

[Scotgirl35]

Looking for peoples thoughts....
DD is 4 (5 in March) and her behaviour is terrible 😞 We've been on a slippery down hill slope for about 12 months now and this Christmas has basically been ruined for herself, her brother and all of us as a family. She is rude, spoilt, aggressive, demanding and daily life just revolves around her. I'm frequently in tears with her and DH who is normally quite patient and 'on her side' is even sick now.
She seems to be naughty on purpose? As if she needs the attention?...yet we feel she gets lots off both DH and I and also extended family. She seems to have no remorse either and does not care if either me and her siblings are upset by her behaviour.
Doing as she is asked is a no go if it doesn't suit her and the smallest of tasks can end up in a complete drama.
School say they have no problem so I'm assuming there's nothing 'wrong' and she's just naughty???
We've tried being really strict and using naughty step, good behaviour charts etc. We've also tried the other tact of ignoring good behaviour and praising good...generally being more relaxed...but this seems to have made things much worse when her behaviour goes uncorrected.
What to do?...after numerous arguments today she has gone to bed saying she hoped when she wakes in the morning I'm dead 😢😢

You don't give any examples of her behaviour so it's hard to judge.

So basically if I ask her do something like get her shoes on because we are going out..and she doesn't want to, she will point blank refuse and say things like "no, you can't make me" until basically I would have to man handle her, physically sit her down and force her to put the shoes on. The whole time she would be trying to hit me and shouting things like "I hate you" "you can't make me". This scenario could be anything...take your uniform off please, help pick the toys up, sit at the table dinner is ready etc etc.
If I try to discipline her she will say things like "don't you speak to me like that" in an aggressive tone. She will also shout at her younger brother saying things like "I hate you" and " you are a horrible boy" (he's 2).
...if I try to explain to her that her behaviour is upsetting everyone she just says she doesn't care? I can force her to 'say sorry' but it's meaningless and she will do the same thing again 5mins later.
Today for example at soft play I gave her a 10min warning we were leaving, then 5 minute etc but when all the other 5 children we were with, aged 3-6, were back at the table with shoes and coats on, I had to ask a friend to watch my toddler and 4 month baby so I could climb into the soft play and physically grab her as she refused to come out and was sticking her tongue out at me and running off 😞

If she refuses to put her shoes on then take her out without them. My dd went through a phase of refusing to put her uniform on in the morning. I rang school and told them that the next time it happened I'd bring her in in her pyjamas with her uniform in a bag. I only had to do it once. We made it as far as the garden before she realised I was serious and she never did it again. Until she will do as she is told I wouldn't take her to soft play etc. Try and arrange to take your other dc while someone stays home with her and make a point of telling her why she is being left behind. If she is shouting and being aggressive then remove her from the room place her in the hallway until she calms down. She is still small enough for you to physically control the situation she needs to understand that the world doesn't revolve around her before she is too big to control.
As far as behaviour at home vs school goes; children with ASD etc often behave well at school because they aren't as secure there they know that if they meltdown at home the people there will still love/like them.