Is anyone else's four year old turning into a monster over the holidays?

[mossyroundhill]

DD woke up a few days ago and seems to have turned overnight, well, horrible really.
She's not at pre-school over summer so there were a few days of her playing up which I assumed was just her settling into a different routine. Then we had a week or so of her being polite, friendly, really helpful, playing nicely with her younger sibling.
She woke up last week and just from then on she's been really badly behaved. Answering back, refusing to do things I ask or listen to me (just shaking her head or saying no, I won't). Huge, huge tantrums, I've been hit, kicked, she's kicked the walls and she thrashes about. Doing things she knows she shouldn't do, seconds after I've nicely asked her not to do it. Hurting her sibling. Speaking to me like shit ("Mum-MY, I'm talking to you!" If I don't respond within 0.2 seconds).
We're doing a good balance of activities outside the house and playing at home. She has one-to-one time with me when her sibling is asleep, this can be up to two hours a day. We have a good bedtime routine. We have time for her to rest during the day. She has time on her own when sibling winds her up.
I've brought back the star chart which has done fuck all, even with a treat she's chosen. We have lots of cuddles and talk about her behaviour in a positive way, but at the same time I don't tolerate any of it, she has three warnings then she doesn't get her star.
I'm really, really losing my patience with her. Probably doesn't sound like much compared to some kids but it's just relentless, nothing works.
Anyone got any advice? Or failing that enough to keep me going till September will do.

Is she starting school inSeptember? My usually lovely polite 4 year old has picked up a demanding teenager like attitude and seems to have dropped please and thank you.

I’m putting it down to a little anxiety around starting school, although she does really claim she is excited. Also, a week of just her on holiday with Grandparents indulging her every whim hasn’t helped either!

Sounds like a typical 4 year old to be honest. You are doing all the right things but it is hard. My approach is...
If you behave nicely a breakfast you can choose 2 TV shows. Followed by if you get dressed and do X, y or z then we will go to the park. If they don't do it then stick to your word and remove the privilege. They'll soon get the message you mean business. Any hitting etc of me or sibling leads to loss of toy or outing for the day. Be very consistent and follow through on threats. I gave up on time out, it just doesn't work for my child. If misbehaving when out and about 2 warnings and then into the car and straight home. Hard if you are out with friends but is effective. Good luck

I found star charts aren't immediate enough and too abstract. Mine don't really care about a sticker, anyway!

My then four year old was a nightmare the summer before she started school. As pp, I put it down to anxiety over starting school

Not to the same extent as yours (no hitting/kicking etc) but my 4 year old has been difficult recently. I’m pretty sure it’s subconscious anxiety around starting school. My 5 year old started school last year and she’s usually an angel but I remember her having a difficult period just before starting school too.

My eldest was difficult before she started school and I had a newborn to contend with . Said newborn is now 4 and also being a terror and not doing what she’s told . Mine seem much better with routine .