I think this is the natural consequence of parents allowing pyjamas downstairs. (I’m not British and in our culture pyjamas outside the bedroom are considered the height of slovenliness)*
I have to respond to this. I am British, and the only time my children ever wore nightwear downstairs was if they were too ill to get dressed and had to lie on the sofa (I'm thinking norovirus here). There's not much that's more slovenly than nightwear outside the bedroom.
That aside:
@Itsmehiimtheproblemitsmee
A few thoughts, in the hope that at least one might be useful.
You had a particular plan in your mind about a nice day off. Your daughter didn't have the same plan in her mind, because she's not a mum who is normally at work. For her, it was probably nice just to be playing at home, rather than being bundled off to school in a rush. Whereas for you, it would have been nice to have had a proper change of scenery with your favourite little person. Neither of you was 'wrong'!
Defiance is very normal in an awful lot of four-year-olds, and I wouldn't start thinking about SN unless you have a very, very good reason for this. If you are generally calm and nice-natured, you're a sitting target for a 4 yo who is testing the boundaries like mad.
It's easy to think if you have an 'easy' small child that you just need to keep on doing what you've been doing. However, all children are challenging at some point; your DD is doing it now. Your job is to decide what really matters, and let the other things go. If you can say yes, say yes. If you say no, you have to mean it.
Don't try to negotiate with a 4 yo. It's okay to pull rank. Rudeness and any kind of aggression result in a consequence (preferably a natural consequence). But don't double punish (I did this at times, and regretted it). And don't threaten punishments which go into the future (things like "if you are rude again, you can't go to X's party next week" are meaningless to a child of that age, and just cause you to have to row back and you then feel crap for backtracking).
Is your DD your only child? I ask because this stuff is generally far easier if you have more than one. If you are all ready to go, and one is not complying, then you just stick them in the car/buggy as they are, take clothes/coats/whatever and tell them that if they want to join in, they need to put their coat/wellies/whatever on, otherwise they'll just have to watch everyone else having fun. They tend to comply at that point. If your DD is an only child, try imagining that she isn't!
Even if you do all this, you'll still have days when you think you've got it all wrong. But every day is a new day, and so long as you say goodnight on good terms, it will be fine.