@priya12 This is stress behaviour. Understanding stress behaviour (dysregulation) would have made my life SO much less stressful with my first 3yo!
The way to deal with stress behaviour is figure out what's causing the stress (which will be multiple things, you don't get stress behaviour from one stressor, but from multiple at once) and reduce enough of them that she's able to cope with the remainder.
Also, work on self regulation tools, but at calmer times. You can't start with self reg when the child is already activated, you need to work with them at other times so that they get comfortable and confident using the tools.
BTW, you can also tell it's stress behaviour because your body is literally telling you that her nervous system is activated, because it's activating yours as well! So no shame on this point and ditch the guilt, noticing that your heart rate is elevating and you're feeding on her stress is a really important step to notice.
Stuart Shanker (amazing resource for self reg info) says there are five domains and when you hit stress behaviour like this, you're probably running into all five. The five domains of stressors are: Emotional, Biological (Sensory), Cognitive, Social and Prosocial. I found this chapter from one of his books online:
https://northstarpaths.com/wp-content/uploads/2020/03/Self-Reg-Chapter-2.pdf
So for emotional I can see - she's struggling with a transition, she knows she's going to have to separate from you soon and that can still be emotional at three, maybe she's anxious about being late or about uncertainty about what will happen when she gets there, maybe there's a pattern where you get angry and she's anxious about triggering that.
Biological/sensory - is all the clothes, hair sensation etc. Temperature regulation may feed in here - kids often hate being asked to put outdoor clothing on when they are still in a heated building for example. This could also be anticipation of the walk.
Cognitive I am not sure - executive functioning skills involved in the tasks of getting ready to leave? Too many things happening at once? Language processing because she is being given a bunch of demands maybe? (I'm still learning this)
Social - you're getting stressed which in turn feeds her to be stressed.
Prosocial - likely she wants to please you and get it "right".
Of course you can't reduce all the stressors. She still has to transition and separate. Those things will continue to be stressful no matter what. And she has to wear clothes. For the others it's less clear what is actually causing the stress and what can be changed, you just have to experiment.
So I think where I would start is to change the timing - can you allow 25 minutes for that 15 minute stretch or even better 30-40 mins? Like whatever currently has to fit into the 15 minute stretch, instead of starting the first part of that 15 minutes before you need to leave, start it earlier. This will give you time to not be stressed yourself. You can take everything more slowly. You can give her one instruction at a time. You can also take time to come down to her level (physically, crouch) and look at her and touch her when you talk, which helps hugely with giving instructions. Also, try to make your voice consciously low and soft, rather than firm or anxious or urgent. There is a really great example of this in the ABCs of Everyday Parenting course on Coursera. When you have more time, you'll be relaxed and if you see her start to escalate into a stressed state, you can take the time to slow down and connect with her to coregulate in whatever way that means. Even just being in front of the child and taking a long deep breath yourself can help because they will typically automatically copy you. You may be able to ask her "OK, what's next?" rather than giving a stream of instructions. You could use techniques like emotion coaching/validating if she is becoming emotional.
Using something like the Ross Greene questions can give you more information about the problem. "I've noticed that you're having trouble with your clothes. What's up?" "Can you tell me more about that?" and reflective listening e.g. she says "MY SLEEVES ARE WRONG" and you reply "You're telling me that your sleeves are wrong." This usually then elicits more information e.g. she may hate it when the sleeve of her shirt gets pushed up inside the sleeve of her sweater (Same, kid, same.) You can then ask if she wants you to fix it, and the next day, you can show her how to hold onto the end of her sleeve, so it doesn't get pushed up inside.
If the problem persists even with more time allowed then you might have to try alleviating different things to see if it makes a difference, but that's where I'd start. But the most important thing is just to reframe what you're seeing - not defiance or brattiness or a child being annoying on purpose, but a child who is struggling and going into an activated, dysregulated state. Just that simple switch can help a lot. But the practical tips help too
Sympathy becayse my 15yo was the same at 3, my current 5yo is the same, and we have to have mornings go a very specific way to keep him calm and regulated. I will say that we are MUCH better at this today than we were with the 15yo! But still, if there is more than one thing out of place because e.g. we are running late then it all goes to hell and he will be doing exactly the same things, and we have a 2yo to get out of the door as well.